/O.  J6 .  i"} , 


SJjPfllogfra/ 

PRINCETON,  N.  J. 


Division 


Section.. 


L&.F  2.  \ 

V.  \3 


Digitized  by  the  Internet  Archive 
in  2018  with  funding  from 
Princeton  Theological  Seminary  Library 


https://archive.org/detaiis/sometypesofattenOOmcco 


Vol.  Xlil 
No.  3 


PSYCHOLOGICAL  REVIEW  PUBLICATIONS 


MAY,  1911 
Whole  No.  55 


THE 

Psychological  Monographs 

EDITED  BY 

JAMES  R.  ANGELL,  University  of  Chicago 
HOWARD  C.  WARREN,  Princeton  University  {Index) 

JOHN  B.  WATSON,  Johns  Hopkins  University  (Review)  and 
ARTHUR  H.  PIERCE,  Smith  College  (Bulletin) 


Some  Types  of  Attention 

BY 

/ 

H.  C.  McComas,  Jr.,  Ph.D.  (Harvard) 
Princeton  University 


An  Investigation  Conducted  in  the  Harvard  and  Princeton  Psychological 


Laboratories 


THE  REVIEW  PUBLISHING  COMPANY 
41  NORTH  QUEEN  ST.,  LANCASTER,  PA. 

AND  BALTIMORE,  MD. 


COMPOSED  AND  PRINTED  AT  THE 


WAVERLY  PRESS 
Bt  The  Wilxjams  &  Wilkins  Company 
Baltimore,  U.  S.  A. 


CONTENTS 


Part  I.  Introductory 

Plan  and  Scope  of  the  Experiments .  i 

Historical  Setting .  3 

Apparatus  and  Subjects .  7 

Part  II.  Experiments 

Span  of  the  Attention .  9 

Concentration  and  Inhibition .  16 

Mobility  of  Attention .  25 

Celerity  of  Attention .  27 

Some  Memory  Factors  in  Attention .  31 

Ideational  Types .  33 

Visual  Perception  and  Attention .  37 

Motor  Factors  and  Perceptual  Attention .  40 

Auditory  Factors  in  Perceptual  Attention .  44 

Part  III.  Correlations 

Correlation  Formula .  47 

Correlation  Results .  50 

Tables  of  Correlations .  56 


Part  I .  Introduction 


THE  PLAN  AND  SCOPE  OF  THE  EXPERIMENTS 

The  experiments  described  in  the  following  pages  were 
designed  to  discover  whether  the  differences  which  appear 
among  individuals,  in  certain  simple  acts  of  the  attention, 
are  indicative  of  typical  traits  of  the  attention,  or  whether 
they  are  fortuitous  and  unrelated.  Individual  differences  in 
attention  are  easily  found  and  have  been  frequently  described, 
but  few  efforts  have  been  made  to  determine  what  traits  go 
together.  Popular  judgments  on  such  questions  are  very 
common.  The  unconscious  sorting  out  of  the  bright  and 
the  dull,  the  absent-minded  and  the  alert  and  many  other 
contrasts,  which  everyone  is  constantly  making  in  his  daily 
relations  with  other  people,  is  a  recognition  of  differences 
in  attention  and  possible  groupings  of  them  for  practical 
purposes.  Teachers  are  very  prone  to  generalize  in  the 
estimates  of  their  students,  and  undoubtedly  many  of  their 
shrewd  discriminations  would  be  borne  out  by  laboratory 
tests.  Though  it  is  exceedingly  probable  that  a  great  many 
convictions  which  have  grown  up  in  the  classrooms  are  not 
based  on  a  sufficient  or  accurate  induction.  Thus,  the 
common  ‘rules’  that  a  fast  reader  remembers  less  than  a 
slow  one,  or  that  the  student  who  learns  quickly  forgets 
more  easily  than  the  plodder  are  specimens  of  the  popular 
correlating  which  would  quickly  lose  their  force  under  care¬ 
ful  observation  or  experiment. 

In  endeavoring  to  detect  typical  traits  of  the  attention  the 
series  of  experiments  to  be  described  were  planned  to  con¬ 
sider  several  characteristic  attentional  acts  and  to  ascertain 
the  individual  differences  which  appeared  in  each.  These 
differences  were  then  studied  and  correlations  sought  by  a 
mathematical  formula.  Throughout  the  entire  work  each 


I 


2 


H.  C.  McCOMAS. 


experiment  has  been  reduced  to  as  simple  terms  as  possible, 
and  every  effort  was  made  to  make  the  measurements  accurate. 

Of  course,  in  all  such  work  the  larger  the  number  of  indi¬ 
viduals  studied  the  better.  It  is  not  practicable,  however,  in 
a  psychological  laboratory  to  examine  great  numbers  and  it 
is  impossible  in  work  of  the  kind  in  hand  to  go  outside  for 
material,  as  the  apparatus  is  not  easily  transported.  In  all 
about  twenty-five  people  participated  in  the  experiments. 
From  these  it  should  be  evident  whether  some  traits  of  atten¬ 
tion  are  indicative  of  types  or  not;  though  a  larger  number 
must  be  examined  before  any  far  reaching  conclusions  are 
attempted.  This  further  study  is  the  more  desirable  as  the 
subjects  were  university  students  and  had  had  from  four  to 
seven  years  of  college  work  behind  them;  which,  of  course, 
would  tend  to  give  them  similar  habits  of  mind.  Far  greater 
diversities  in  concentration,  for  example,  would  probably  be 
found  among  an  equal  number  of  men  chosen  at  random  in 
the  street.  This  uniformity  of  training  is  a  disadvantage 
in  studies  of  natural  differences,  but  the  advantage  of  having 
college-bred  subjects  In  some  measure  compensates  for  it. 
For  much  of  the  work  calls  for  introspection,  which  could 
hardly  be  obtained  from  those  who  had  no  such  training. 

The  number,  and  therefore,  the  character  of  the  experi¬ 
ments  were  limited  by  the  conditions  of  the  experimentation. 
For  example;  no  work  on  the  influence  of  fatigue  upon  atten¬ 
tion  was  attempted,  when  it  became  apparent  that  the  one 
hour  allotted  each  experiment  would  not  suffice  to  induce 
fatigue  in  all  the  subjects;  nor  was  it  practicable  to  find  how 
the  personal  interests  and  habits  of  thought  of  the  various 
observers  affected  attention.  Questions  of  involuntary  atten¬ 
tion  and  of  fluctuations  were  not  studied ;  not  because  they  are 
not  of  importance  in  finding  Types,  but  because  the  diffi¬ 
culties  to  be  overcome  in  preparing  conditions  were  too  time- 
consuming  to  admit  them.  To  obtain  material  which  would 
permit  accurate  comparison  of  one  subject’s  results  with 
those  of  each  of  the  others  it  was  thought  advisable  to  limit 
the  field  to  tachlstoscopic  work  as  far  as  possible.  Differ¬ 
ences  which  creep  in  when  the  apparatus  Is  frequently 


SOME  TYPES  OF  ATTENTION. 


3 


changed,  were  thus  obviated.  This  restricted  the  field  to 
visual  work,  in  large  measure,  but  allowed  ample  scope  for 
individual  differences  to  show  themselves.  In  the  tests  for 
‘span’  different  classes  of  objects  were  exposed,  which  called 
for  different  attitudes  of  attention  in  the  subjects  and  showed 
individual  differences  clearly.  So  in  the  other  tachisto- 
scopic  tests;  a  comparatively  wide  variety  of  experiments 
was  found  practical. 

The  scope  of  the  work,  therefore,  is  limited  to  groups  of 
university  students,  each  group  studied  during  one  college 
year  in  one  hour  periods.  The  apparatus  largely  restricts 
the  work  to  attention  in  visual  perception. 

The  plan  of  the  experiments  under  such  conditions  shaped 
itself  into  a  study,  first,  of  the  characteristic  span  of  attention 
of  each  subject  in  observing  several  classes  of  objects,  then, 
the  ability  to  concentrate  upon  certain  things  and  to  inhibit 
others,  this  led  into  an  examination  of  the  differences  in  the 
faculty  of  turning  the  attention  from  one  class  of  interests 
to  another  and  the  quickness  with  which  this  could  be  done. 
Throughout  the  work  the  experimenter  noticed  differences  in 
the  records  of  subjects  due  to  the  memory  factor.  These 
were  studied  with  a  view  to  detecting  a  possible  correlation 
between  memory  and  attention.  Finally,  the  question  of 
the  relation  of  memory  types  to  types  of  attention  concludes 
the  experimentation.  The  results  are  given  in  each  chapter 
in  tables  which  show  the  relative  capacities  of  the  subjects 
for  that  experiment.  This  determines  the  subject’s  rankings 
which  are  used  in  the  correlation  tables.  From  the  corre¬ 
lations  the  conclusions  are  drawn  concerning  the  possibilities 
of  Types  of  Attention,  in  the  experiments  used. 

HISTORICAL  SETTING 

There  is  very  little  literature  upon  Types  of  Attention. 
Scattered  references  may  be  found  in  recent  studies,  but  no 
thoroughgoing  effort  has  been  made  to  find  actual  typical 
characteristics  in  the  individual  differences  in  attention. 
The  nearest  approach  to  the  experiments  in  hand  are  the 


4 


H.  C.  McCOMAS. 


tests  made  for  individual  differences  in  several  faculties. 
Some  of  these  we  shall  consider  later. 

While  the  great  body  of  psychological  literature  is  silent 
upon  the  matter  of  Types  of  Attention  it  nevertheless  bears 
witness  to  them  in  a  very  unique  way.  For  many  writers 
upon  philosophical  and  psychological,  or  near-psychological, 
topics  since  Plato’s  time  have  touched  upon  the  activities 
of  attention,  and  their  opinions  give  an  interesting  insight 
into  their  own  mental  processes.  We  find  throughout  the 
history  of  the  theories  of  attention  two  general  classes  of 
opinion^  The  one  holds  that  the  attention  is  more  or  less 
subjected  to  the  play  of  stimuli  upon  the  mind,  that  the  in¬ 
ward  direction  of  one’s  course  of  thought  is  to  be  found  in 
the  influence  of  his  surroundings.  The  other  view  empha¬ 
sizes  the  influence  of  the  mind  upon  the  activity  of  attention 
regardless  of  the  external  world.  It  magnifies  the  domina¬ 
tion  of  a  will  or  a  self.  Of  course  the  general  philosophy  of 
a  thinker  will  modify  his  conception  of  each  chapter  in  psy¬ 
chology;  but,  in  spite  of  that,  the  disposition  of  his  own 
thinking  will  tend  to  be  the  criterion  by  which  he  will  be 
guided.  If  he  is  easily  distracted  by  his  surroundings,  if  he 
finds  it  difficult  to  concentrate  upon  intellectual  problems 
rather  than  perceptual,  if  his  attention  is  of  a  discursive 
nature,  passing  easily  from  one  subject  to  another,  then 
nothing  could  be  more  natural  than  the  conlcusion  that  the 
attention  is  directed  by  stimuli  rather  than  by  will.  On  the 
other  hand,  a  mind  which  readily  concentrates  upon  abstract 
themes,  ignoring  the  passing  appeals  of  the  outer  world, 
feeling  its  ability  to  turn  now  to  one  phase  of  the  subject 
considered,  now  to  another,  without  let  or  hindrance,  is 
very  apt  to  be  a  mind  which  concludes  it  possesses  an  inde¬ 
pendent  control  over  the  attention.  From  such  experiences 
the  two  divergent  types  of  theory,  the  involuntary  and  the 
voluntary,  undoubtedly  evolved.  They  are  descriptive  of 
two  types  of  attention,  insofar  as  they  are  based  on  intro- 

^D.  Braunschweiger,  Die  Lehre  von  der  Aufmerksamkeit  in  der  Psychologic  des  i8. 
J ahrhunderts ;  L.  L.  Uhl,  Attention,  an  Historical  Summary  of  the  Discussions  Con¬ 
cerning  the  Subject. 


SOME  TYPES  OF  ATTENTION. 


5 


spection,  and  few  men  are  so  abstract  in  their  treatment  of 
such  matters  that  the  evidence  of  their  own  mental  life  does 
not  affect  their  systems  of  thought. 

Such  differences  as  those  appearing  between  the  positions 
taken  by  Condillac,  Bonnet  and  Helvetius  on  the  one  hand 
and  by  Reid  and  Stewart  on  the  other  bespeak  more  than 
philosophic  and  literary  differences.  The  natural  differ¬ 
ences  of  race  and  mental  traits  come  into  the  writings  and 
account  in  large  measure  for  their  attitudes  on  the  question 
of  attention. 

It  is  perfectly  legitimate  to  assume  that  we  have  the  mate¬ 
rials  for  two  types  of  attention,  at  least,  in  the  mental  life  of 
psychologists  and  philosophers.  It  would  be  a  valuable 
study  if  the  influence  of  these  fundamental  mental  traits 
were  traced  out  in  the  systems  of  philosophy  which  these 
minds  found  the  most  acceptable  and  congenial. 

Baldwin  finds  five  classes  of  modern  psychologists;  those 
who  maintain  that  the  affective  element  is  dominant  in 
attention,  namely  Horwicz  and  Ribot;  those  who  find  in 
attention  an  original  activity  of  the  mind;  Stumpf,  Ladd, 
Ward  and  Jodi;  those  who  refer  the  fundamental  factors  of 
attention  to  intensity  of  sensation  and  perception  and  their 
psychic  reinforcement,  such  as  Bradley  and  Muller;  those  who 
see  attention  as  the  outcome  of  inhibition.  Terrier  and  Ober- 
steiner;  and  the  champions  of  the  theory  that  attention  is  to 
be  understood  in  the  light  of  the  motor  factors,  Baldwin, 
Lange,  and  Stout.  In  the  last  group  of  theories  we  should 
consider  Munsterberg’s  ‘Action  theory’  and  the  theories  of 
McDougall  and  Sherrington. 

Not  until  the  time  of  Francis  Galton  do  we  find  any  con¬ 
sistent  study  of  individual  differences.^  His  suggestions  were 
carried  out  experimentally  among  school  children  by  Gilbert, 
Boas,  Bolton  and  others.  However,  the  most  nearly  related 
to  Types  of  Attention  is  the  work  of  H.  Griffing  On  the  Devel¬ 
opment  of  Visual  Perception  and  Attention  in  which  he  tries 
to  establish  a  correlation  between  the  Span  of  Attention  and 


^Inquiries  into  the  Human  Faculty.  1883. 


6 


H.  C.  McCOMAS. 


the  mental  ability  of  the  subjects.  Baldwin’s  doctrine  that 
the  attention  is  as  subject  to  ideational  differences  as  memory 
and  imagination,  which  appeared  in  his  Mental  Development 
was  not  based  on  any  experimental  fact.  In  the  work  of 
Henri  et  Binet,  La  Psychologie  Individuelle,  1896,  we  have 
the  recognition  of  the  fact  that  attention  may  differ  in  typical 
ways  among  individuals.  Later  Binet  endeavored  to  dis¬ 
prove  Gilbert’s  correlation  between  mental  ability  and  span. 
The  work  was  done  on  auditory  span.  Binet  and  Vaschide 
made  many  experiments  for  differences  in  reaction-time, 
memory  and  general  mental  ability,  but  none  bearing  directly 
on  our  subject.  The  article  of  S.  E.  Sharp  upon  Individual 
Psychology  gives  a  very  good  resume  of  what  work  Binet 
did  on  attention.^  He  sought  to  determine  the  degree  of 
attention  by  having  his  subjects  cancel  certain  letters  as 
they  read  a  page.  The  range  of  attention  was  sought  by 
having  the  subjects  read  aloud  and  write  the  alphabet  simul¬ 
taneously.  Both  methods  are,  of  course,  very  faulty  and 
no  one  should  expect  clear-cut  results  from  them.  In  L.  W. 
Stern’s  Ueher  Psychologie  der  individuellen  Differ enzen,  1900, 
we  have  a  very  able  treatment  of  Types  in  psychology.  In 
attention  he  finds  the  concentration  (Konzentration)  and 
the  expansive  (Elastizitat)  features  of  attention  indicative 
of  two  types.  Also,  he  finds  typical  differences  in  constancy 
of  application  and  the  intermittency  of  concentration.  He 
maintains  that  the  psychic  energy  used  in  attention  varies. 
This  explains  some  of  the  phenomena  of  differences  in  morn¬ 
ing  and  evening  workers  and  of  sleep  as  well.  He  does  not 
attempt  any  large  correlations  between  types. 

Kraepelin  and  Cron  in  their  work  Ueher  die  Messung  der 
Auffassungsfdhigkeit  made  tests  of  the  simpler  mental  fac¬ 
tors  and  found  the  results  far  from  satisfactory.  This  fail¬ 
ure  of  correlation  is  rather  characteristic  of  experiments  in 
individual  differences;  witness  the  paucity  of  results  from 
the  experimentation  of  this  character  by  Wissler,  Thorndike 
and  others  upon  students.  Spearman,  nevertheless,  believed 


^Amer.  J .  of  Psychol.,  x,  p.  329. 


SOME  TYPES  OF  ATTENTION. 


7 


from  his  experiments  that  a  correlation  could  be  found  between 
all  forms  of  sensory  discrimination  and  the  more  complicated 
intellectual  activities  of  practical  life.  He  sums  up  his  results 
thus:  “All  branches  of  intellectual  activities  have  in  com¬ 
mon  one  fundamental  function  (or  group  of  functions), 
whereas  the  remaining  or  specific  elements  of  the  activity  seem 
in  every  case  to  be  wholly  different  from  that  of  all  others.” 

The  discussions  of  the  work  of  Miinsterberg,  Cattell, 
Jastrow,  Calkins,  and  others  which  deal  with  the  larger 
problems  of  Individual  Differences  need  not  engage  us  here. 
Our  retrospect  upon  the  historical  feature  of  Types  of  Atten¬ 
tion  shows  the  need  of  a  beginning,  at  least,  in  the  literature 
of  this  subject. 


APPARATUS  AND  SUBJECTS 

The  apparatus  used  in  nearly  all  of  the  experiments  was  a 
very  simple  form  of  tachistoscope.  It  was  fastened  to  a  low 
table  and  leaned  toward  the  subject,  so  that  he  could  conven¬ 
iently  place  his  eye  close  to  the  shutter-opening.  It  was 
simply  constructed  with  a  base-board  36  x  14  inches  which 
sustained  supports  holding  a  similar  board  above  it.  This 
upper  board  was  arranged  with  an  incline  toward  the  sub¬ 
ject.  It  was  16  inches  above  the  base-board  along  the  line 
farthest  from  the  subject  and  12  inches  along  the  line  next 
him.  A  frame  about  3  inches  high  held  an  automatic  camera 
shutter  over  an  orifice  in  the  center  of  this  inclined  upper 
board.  Immediately  beneath  was  a  heavy  grey  card,  par¬ 
allel  with  this  upper  board,  and  17  inches  from  the  subject’s 
eye.  Upon  this  card  the  smaller  cards,  containing  the  objects 
to  be  observed,  were  placed.  The  shutter  was  controlled  by 
a  pneumatic  device.  A  pendulum,  regulated  to  traverse  its 
amplitude  twice  in  a  second,  hung  beside  the  experimenter’s 
chair.  The  experimenter  was  hidden  from  the  subject  by  a 
cloth  screen  which  was  suspended  by  a  rack  on  the  upper 
board.  The  whole  frame  was  covered  with  black  card-board, 
except  the  back  which  was  left  open  for  light  and  to  enable 
the  experimenter  to  change  the  exposed  objects  easily. 


8 


H.  C.  McCOMAS. 


Nothing  was  visible  to  the  subject  but  the  screen  upper, 
board  and  shutter.  When  the  shutter  sprang  open  the  white 
card,  7  x  5^  inches,  which  held  the  objects  to  be  observed, 
was  clearly  in  view.  The  letters  used  were  A  inches  high  and 
were  black.  The  colored  letters  were  about  |  inch  in  height, 
and  the  colored  figures  were  from  |  to  i  inch  in  height.  Where 
the  squares  of  color  were  used,  they  were  about  f  inch  each 
way. 

Another  apparatus  was  used  in  the  experiments  upon  visual 
and  auditory  attention  which  might  be  termed  a  rotary 
tachistoscope.  It  was  a  wooden  disk  24  inches  in  diameter 
hung  upon  an  axle,  and  connected  by  a  rubber  belt  with  a 
dynamo  whose  wheel  connections  admitted  of  several  speeds. 
Thirty-eight  words  in  white  letters  were  fastened  at  regular 
intervals  near  the  circumference.  Immediately  in  front  of 
the  wooden  disc  was  a  black  card-board  disc  with  slits  oppo¬ 
site  the  words.  When  these  two  rotated  together,  words 
flashed  up  before  the  eye  and  disappeared  without  their 
motion  being  observable.  The  eye  was  kept  in  position  by 
looking  through  another  slit  card-board  about  i  foot  from  the 
black  card  disc. 

In  the  work  at  the  Laboratory  in  Princeton  a  tachisto¬ 
scope  was  constructed  from  two  black  card-board  discs 
50  c.m.  in  diameter.  Each  disc  had  a  quadrant  cut  out  of  it, 
and  they  were  rotated  with  half  of  the  surface  of  one  disc 
covering  half  of  the  surface  of  the  other.  Where  the  cut  por¬ 
tions  coincided  the  observer  had  a  clear  view  of  the  card  to  be 
exposed.  Attached  to  the  wheel,  on  which  one  of  the  discs 
was  fastened,  were  several  copper  fingers.  These  made  and 
broke  electric  currents  to  magnets  and  bells,  at  the  moment 
when  the  card  was  exposed. 

The  subjects  participating  in  the  first  year’s  series  of  experi¬ 
ments  were  four  graduate  students  in  Harvard  University,  a 
practicing  physician  and  a  professor  in  psychology.  In  the 
second  year  three  of  the  subjects  were  Instructors,  the  others 
being  graduate  students  who  had  had  considerable  labora¬ 
tory  experience.  Two  of  these  were  women.  In  the  third 
year  the  nine  young  men  were  all  undergraduates  in  Princeton. 


SOME  TYPES  OF  ATTENTION. 


9 


Part  II.  Experiments 

THE  SPAN  OF  ATTENTION 

In  measuring  attention  we  feel  the  need  of  an  exact  defi¬ 
nition  of  what  we  are  measuring  more  keenly  than  in  any 
other  treatment  of  the  subject.  Our  work  will  be  confusion 
worse  confounded  if  we  do  not  have  a  clear-cut  idea  of  just 
what  is  being  measured.  Unfortunately  we  encounter  the 
old  difficulties,  which  are  met  in  every  attempt  to  define  con¬ 
sciousness,  those  of  implying  the  thing  defined  in  the  defini¬ 
tion.  This  ‘  circulus  in  definiendo  ’  is  a  very  subtle  snare  just 
here.  Attention  is  a  characteristic  of  every  mental  act,  we 
are  always  in  the  center  of  it,  we  cannot  get  away  from  it  and 
survey  its  borders  from  without.  Nevertheless,  we  may  make 
clear  what  is  meant  in  the  present  chapter  by  attention,  with 
illustration  and  comparison. 

When  we  look  at  a  printed  page  there  is  always  some  portion  of  it, 
perhaps  a  word,  which  we  see  more  clearly  than  the  rest;  and  out  beyond 
the  margin  of  the  page  we  are  still  conscious  of  objects  which  we  see 
only  in  an  imperfect  way.  The  field  of  consciousness  is  apparently  like 
this  visual  field.  There  is  always  a  central  point  of  which  we  are  momen¬ 
tarily  more  vividly  conscious  than  anything  else.  Fading  gradually 
away  from  this  point  into  vague  and  vaguer  consciousness,  is  a  margin 
of  ideas,  or  objects,  of  which  we  are  aware  in  some  sort  of  mental  indirect 
vision.  This  fact  that  consciousness  always  has  a  focal  point,  which 
reveals  the  momentary  activity  of  the  mind,  is  what  is  meant  by  the 
fact  of  attention.* 

This  is  expressed  graphically  by  means  of  five  concentric 
circles.  The  outermost  circle  representing  unconsciousness; 
the  next  inner  circle,  subconsciousness;  the  next,  diffused 
consciousness;  the  circle  next  to  the  center  is  called  active 
consciousness  or  attention  and  the  center  circle  represents 
apperception,  which  synthesizes  all  mental  data. 

Our  problem  is  the  measuring  of  this  focal  area  in  con¬ 
sciousness.  That  it  is  not  anything  like  so  simple  and  static 


lAngell,  J.  R.,  Psychology,  p.  65. 


lO 


H.  C.  McCOMAS. 


a  thing  as  the  series  of  circles  might  imply  goes  without 
saying.  Indeed,  the  mobility  and  elasticity  of  that  central 
area  are  equalled  only  by  the  vagueness  and  uncertainty 
of  the  several  grades  or  degrees  of  consciousness  represented. 
It  would  seem  at  first  sight  that  the  problem  of  determining 
where  this  central  clearness  ends  and  the  peripheral  obscur¬ 
ity  begins  is  as  thankless  a  task  as  finding  the  line  between 
candle-light  and  the  darkness  enveloping  it.  There  are, 
fortunately,  some  features  in  the  process  which  lend  us  mate¬ 
rial  aid.  As  Wundt  showed,  many  years  ago,  every  process  of 
attention  has  two  factors,  the  one  increases  the  clearness  of 
an  idea  or  perception,  the  other  diminishes,  by  inhibition, 
other  available  impressions  or  memory-images.  So  our 
area  of  light  is  heightened  in  its  clearness  and  our  circumfer¬ 
ence  of  obscurity  is  darkened,  making  the  margin  of  uncer¬ 
tainty  between  the  two  narrower  than  it  first  appeared,  though 
all  too  broad  at  that.  Titchener  adds. 

Attention,  in  other  words,  means  a  redistribution  of  clearness  in  con¬ 
sciousness,  the  rise  of  some  elements  and  the  fall  of  others,  with  an  accom¬ 
panying  total  feeling  of  a  characteristic  kind.”^ 

A  large  number  of  careful  experiments  have  been  made  to 
measure  this  span  of  clearness.  Usually  they  have  sought 
to  catch  the  act  of  attention  in  an  instant  of  time  and  to  take 
a  sort  of  psychological  snap-shop  of  its  processes.  This,  of 
course,  applies  to  attention  concerned  with  spacial  percep¬ 
tions,  not  with  temporal,  and  it  is  with  the  spacial  aspect  we 
shall  deal.  A  tachistoscope  is  usually  employed  which  either 
illuminates  the  field  observed  for  a  fraction  of  a  second  or 
exposes  the  field  by  the  opening  of  a  shutter.  The  observer 
has  a  fixation  point  in  the  middle  of  the  field  which  obviates 
loss  of  time  by  eye  movement,  and  makes  measurements 
more  exact.  Wundt  says: 

careful  introspection  easily  succeeds  in  fixating  the  state  of  conscious¬ 
ness  at  the  moment  the  impression  arrives,  and  in  distinguishing  this 
from  the  subsequent  acts  of  memory .  .  .  these  experiments . 


^Titchener,  E.  B.,  The  Psychology  of  Feeling  and  Attention,  p.  183. 


SOME  TYPES  OF  ATTENTION. 


II 


show  that  the  scope  of  attention,  when  it  is  kept  at  its  maximum  intens¬ 
ity,  remains  constant  only  when  the  impressions  are  held  apart  as  in  the 
case  of  isolated  lines,  numbers,  letters^  Six  such  simple  impressions 
can,  under  favorable  conditions,  be  apperceived  in  the  same  instant. 
As  soon  as  the  impressions  are  bound  together  in  complexes  the  number 
included  in  the  scope  of  attention  changes. 

This  conclusion  is  borne  out  by  the  experiments  of  Gold- 
scheider  and  Muller  at  Berlin^.  They  found  that  for  iso¬ 
lated  lines  exposed  for  only  yiv  of  a  second,  four  or  at  most 
five  could  be  recognized.  When  the  lines  were  grouped  in 
symmetrical  forms  a  larger  number  could  be  apperceived. 
Cattell,  Erdmann  and  Dodge  corroborate  these  findings  in 
their  experiments  upon  the  psychology  of  reading. 

We  may  be  sure,  then,  that  the  process  of  attention  when 
concerned  with  a  few  unrelated  impressions  is  unlike  the 
process  with  which  we  are  familiar  in  the  ordinary  activity 
of  attention;  where  we  naturally  associate  and  assimilate 
the  impressions  and  retain  these  synthesized  groups  in  our 
memory.  But  we  may  not  be  sure  as  to  just  how  far  these 
so-called  unrelated  objects  fail  to  be  apperceived.  In  a  few 
trial  experiments  upon  this  problem  I  quickly  discovered  that 
the  ability  to  apperceive  in  groups  varied  in  the  same  indi¬ 
vidual  for  different  arrangements  and  varied  widely  in  differ¬ 
ent  individuals.  Not  only  was  this  confusing  situation 
present,  but  a  more  subtle  difficulty  presented  itself  in 
the  fact  that  a  certain  amount  of  grouping  may  occur  in  an 
unconscious  manner.  That  is,  the  lines  vaguely  suggest  a 
box,  a  house,  or  a  face,  but  not  clearly  enough  to  make  it 
a  matter  of  comment,  or  even  of  notice,  unless  questioned  by 
the  experimenter.  In  such  cases  the  span  of  attention  will 
appear  large,  though  the  cause  is  a  purely  accidental  one. 
This  occasional  activity,  the  assimilating  of  impressions  into 
larger  wholes,  cannot  be  entirely  excluded  from  any  experi¬ 
ment  upon  attention.  It  is  one  of  the  several  disconcerting 
factors  which  we  must  seek  to  minimize.  I  found,  however, 


iwundt,  W.,  Outlines  of  Psychology,  Third  English  edition,  p.  236. 
^Zeitschrift  Klin.  Med.,  Bd.  xxiii,  p.  13 1. 


12 


H.  C.  McCOMAS. 


in  many  hundreds  of  experiments  that  the  subject’s  intro¬ 
spection  and  the  report  he  gave  went  very  well  hand  in  hand. 
That  is,  when  a  series  of  words  suggested  a  sentence  and  so 
gave  unusually  large  returns,  or  when  several  colors  grouped 
themselves  as  shades  of  a  fundamental  color,  I  could  detect 
the  ease  in  which  the  report  was  made  and  so  corrections 
could  be  made,  or  the  result  discarded.  I  do  not  believe  that 
this  grouping  is  as  prevalent  in  those  experiments  where  the 
impressions  themselves  are  a  complex  such  as  words,  colored 
figures,  or  geometrical  forms,  as  in  those  simpler  presenta¬ 
tions  where  it  is  difficult  to  arrange  mere  dots  and  dashes 
so  that  they  will  not  suggest  some  form  or  figure  to  the  eye. 
Rather  the  association  will  arise  from  alliteration  or  rhymes 
in  the  words  or  a  serial  order  in  the  numbers,  etc.  But  these 
difficulties  are  in  large  measure  obviated  after  a  little  expe¬ 
rience  and  practice  in  arranging  the  material  to  be  presented. 
For  this,  and  other  reasons,  the  experiments  which  I  made 
to  measure  the  span  of  attention  were  uniformly  of  longer 
duration  in  exposure,  and  of  more  varied  and  richer  content 
in  impression; — tachistoscopically  speaking,  they  are  less  of 
a  ‘  snap-shot  ’  and  more  of  a  ‘  time-exposure  ’  than  those  class¬ 
ical  experiments  from  which  we  have  been  quoting. 

The  method  best  adapted  to  detect  individual  differences 
in  the  scope  of  attention  must  be  one  which  enables  the  atten- 
tional  processes  to  act  in  as  normal  a  way  as  is  possible  in 
laboratory  work  and  which  gives  the  experimenter  a  compre¬ 
hensive  view  of  what  these  processes  are.  Such  a  method, 
I  believe,  is,  at  least,  approximated  in  the  work  now  to  be 
described. 

Three  series  of  experiments  were  made  extending  over 
several  months  and  giving  each  subject  a  sufficient  number  of 
trials  to  enable  him  to  express  in  averages  his  characteris¬ 
tics.  Any  one  lot  of  experiments,  taking  the  subject  for  one 
hour  only,  would  not  in  all  probability,  tell  a  true  story.  I 
recall  one  subject  whose  results  were  fully  20  per  cent  better 
at  one  time  than  at  another.  It  was  a  very  extreme  case; 
but  the  condition  of  the  subject,  if  fatigued,  nervous,  confused 
by  the  experiment  or  what-not,  will  affect  the  results  of  his 


SOME  TYPES  OF  ATTENTION. 


13 


work.  This  objection  is  done  away  with  by  the  number  of 
experiments  and  the  wide  variations  in  time  between  them. 

As  Dearborn  found  it  necessary  to  vary  the  style  and  sub¬ 
ject  matter  in  his  reading  tests,  so  I  found  it  necessary  to  vary 
the  classes  of  objects  exposed.  As  we  shall  see  later,  the 
sensory  and  motor  elements  entering  into  attention  vary  in 
their  proportions  for  words  and  colors.  With  colors  a  visual 
memory  image  usually  persists;  this  seldom  occurs  for  words. 
Were  the  tests  made  for  one  class  of  exposures  only  we  should 
probably  have  errors  creeping  in  from  differences  in  ideational 
type.  To  escape  this  I  have  taken  one  series  of  experiments 
with  the  attention  upon  words,  one  with  the  attention  upon 
colors,  one  with  the  attention  upon  figures  and  letters,  and  I 
have  used  the  sum  of  these  results  to  represent  the  Span  of 
Attention  for  the  several  subjects. 

It  became  apparent  early  in  the  work  that  a  time  exposure 
of  three  seconds  was  too  long  for  many  of  the  subjects.  One 
thing  inhibited  another  and  there  was  always  a  feeling  that 
much  more  had  been  attended  to  than  could  be  reported.  It 
also  became  as  quickly  apparent  that  a  half  of  a  second  was 
too  short  a  period.  For  in  this  class  of  experiments  the  eye 
had  no  fixation  point  and  would  usually  catch  two  or  three 
objects,  but  would  fail  to  survey  the  entire  field.  It  was 
merely  a  matter  of  where  the  eye  chanced  to  rest  that  deter¬ 
mined  the  class  and  number  of  objects.  After  trying  several 
fractions  of  a  second  it  seemed  advisable  to  use  exactly  one 
second’s  time  exposure.  This  enabled  the  subject  to  survey 
an  entire  card,  and  did  not  permit  him  to  overload  his  mind 
with  observations  which  could  not  be  retained.  It  also 
seemed  to  be  an  opportune  time  for  preventing  the  grouping  of 
objects,  such  as  occurs  with  long  time  exposures.  Associa¬ 
tions  would  occur  occasionally,  but  not  frequently.  Indeed, 
five  monosyllabic  words  were  frequently  given  without  the 
subject  forming  any  idea  of  their  meaning,  until  they  were 
reported. 

At  first  the  subject  was  requested  to  write  all  that  had  been 
observed.  This  had  the  effect  of  driving  many  things  out 
of  mind  for  several  subjects,  especially  those  whose  memory 


14 


H.  C.  McCOMAS. 


images  did  not  seem  as  clear  or  of  as  long  duration  as  the 
majority  of  subjects.  So  the  plan  of  giving  a  verbal  report 
was  adopted,  which  entirely  altered  the  results  for  several 
subjects.  More  in  detail  the  experiments  were  as  follows: 

In  series  No.  i,  (see  Table  i)  50  exposures  were  made  of 
10  colors,  upon  the  regular  cards,  with  the  regular  one  second 
exposure.  The  colors  were  shown  to  the  subject  before  the 
experiment  began,  in  order  to  familiarize  the  subject  with 
the  kind  of  color  to  be  exposed  and  to  learn  his  nomenclature 
for  colors.  All  that  was  insisted  upon  was  a  sufficiently 
clear  report,  to  make  certain  that  the  colors  named  had  been 
actually  perceived. 

In  series  no.  2  (see  Table  II)  20  exposures  were  made  of 
cards  containing  5  three-letter  words  and  five  colored  letters 
or  numbers.  The  attention  was  directed  to  the  words  in 
order  to  involve  the  speech-motor  factor  in  attention.  If 
other  things  than  words  were  perceived  they  were  allowed  to 
count  in  the  total  of  things  spanned  by  the  attention.  The 
proportion  of  objects  perceived  which  were  not  in  the  class 
attended  to  is  exceedingly  small;  as  we  shall  see  later.  The 
totals  are,  therefore,  a  satisfactory  index  of  span  for  this 
class  of  work. 

In  series  no  3  (see  Table  III)  20  exposures  were  made  of 
the  same  class  of  cards  as  in  series  no.  2 ;  but  the  attention  was 
directed  in  this  case  to  the  colored  letters  and  numbers.  The 
purpose  in  this  was  to  submit  a  class  of  objects  to  the  subject’s 
attention  which  were  intermediate  between  the  color-class 
and  the  word  class.  For  it  had  been  noted  n  previous  experi¬ 
ments  that  the  setting  of  the  attention  was  introspectively 
different  for  these  two  classes  of  objects. 

In  Table  IV  the  totals  for  these  three  series  were  given  for 
each  subject;  thus,  the  number  of  colors  ‘A’  perceived  in  the 
first  series  was  215,  the  number  in  the  second  series  was  97, 
and  in  the  third  206.  The  total  number  of  objects  attended  to 
in  the  n'nety  experiments  was  518.  That  is,  ‘A’  attended  to 
an  average  of  5.75  objects  for  each  exposure.  This  figure 
or  the  total  itself  is  the  index  of  'A'  for  Span  in  this  class  of 
experiments. 


SOME  TYPES  OF  ATTENTION. 


15 


TABLE  I  TABLE  II 


SUBJECTS 

TOTALS 

CR. 

AV. 

MV. 

TOTALS 

CR. 

AV, 

MV. 

A . 

215 

4 

4-30 

0.58 

97 

3 

485 

I  .  18 

B . 

205 

7 

4. 10 

0.62 

86 

6 

430 

0.80 

C . 

223 

4.46 

0.62 

70 

10 

3  so 

0.90 

I) . 

i6r 

9 

3.22 

o-SS 

96 

4 

4.80 

1 .02 

li . 

222 

3 

4  44 

0.44 

106 

2 

5-30 

I  13 

F . 

141 

10 

2.82 

0.40 

72 

9 

3.60 

0-55 

G . 

213 

sl 

4. 26 

0-57 

74 

8 

3-70 

0.93 

H . 

199 

8 

398 

0.46 

88 

5 

4.40 

0.88 

J . 

213 

si 

4. 26 

0.62 

84 

7 

4.20 

0.90 

K . 

223 

15 

4.46 

0.69 

125 

I 

6.25 

1. 14 

TABLE  III 

TABLE  IV 

SUBJECTS 

TOTALS 

CR. 

AV. 

MV. 

TOTALS 

CR. 

AV. 

A . 

206 

I 

10.30 

2.04 

S18 

2 

5-75 

B . 

137 

8 

6.8s 

1.44 

428 

7i 

4-75 

C . 

169 

5 

8.45 

1-74 

462 

5 

S13 

D . 

122 

10 

6. 10 

1 .04 

379 

9 

4.21 

E . 

i8s 

2 

9-25 

1 . 64 

513 

3 

5  70 

F . 

123 

9 

6.15 

I -25 

336 

10 

3-73 

G . 

141 

7 

7  05 

1 . 12 

428 

7i 

4-75 

H . 

166 

6 

8.30 

1 .60 

453 

6 

S03 

J . 

172 

4 

8.60 

1.30 

469 

4 

5.20 

K . 

182 

3 

9 . 10 

1 .62 

53° 

I 

5-88 

C.R.  =  Correlation  Rank. 
Av.  =  Average. 

M.  V.  =  Mean  Variation. 


From  these  tables  it  appears  that  there  are  large  individual 
differences  between  subjects  in  their  span  of  attention.  Thus, 
‘K’  has  half  again  as  large  a  span  as  'F';  though  several 
have  span  results  quite  close  together  ‘  B  ’  and  ‘  G  ’  having 
the  same  totals. 

In  the  table  of  correlations  it  will  be  seen  that  Table  III 
correlates  with  Tables  I  and  II,  but  that  Tables  I  and  II  do 
not  correlate.  This  shows  there  is  a  sufficient  difference 
between  the  word-class  and  the  color-class  to  affect  the  atten¬ 
tion  quite  differently.  It  also  shows  that  the  experiments  are 
successful  In  measuring  a  characteristic  spanning  of  the  atten¬ 
tion;  for  the  first  series  and  the  third,  between  the  perform- 


i6 


H.  C.  McCOMAS. 


ance  of  which  several  months  elapsed,  have  the  correlational 
coefficient  of  0.48. 

Another  evidence  of  the  accuracy  of  the  experiments 
appears  in  the  tables  for  averages  and  mean  variations 
from  the  averages.  It  is  not  possible  to  find  any  Probable 
Error  in  these  measurements  for  an  unusually  large  or  small 
result  does  not  necessarily  indicate  an  error  of  any  kind. 
The  value  of  the  experiments  would  be  greatly  reduced,  how¬ 
ever,  if  each  subject  varied  very  greatly  from  his  average,  for 
no  figure  would  than  represent  his  span  accurately  enough  to 
permit  comparison  with  the  others.  When  the  averages  in 
the  tables  above  are  compared  with  their  mean  variations  it 
will  be  seen  that  the  variation  is  but  a  small  part  of  the  aver¬ 
age  (usually  a  sixth,  occasionally  a  fourth).  So  the  average 
is  amply  representative  of  the  subject  for  comparison.  The 
average  is  not  given  in  succeeding  experiments  as  it  was  found 
that  the  actual  totals  of  results  give  a  more  accurate  ranking 
for  correlations. 

The  correlations  for  the  above  experiments,  as  they  com¬ 
pare  with  each  other  and  as  they  compare  with  the  other 
experiments  of  the  thesis,  are  all  given.  A  separate  table  is 
also  given  of  those  correlations  which  are  sufficiently  above 
the  Probable  Error,  for  this  method  of  correlating,  to  indi¬ 
cate  significant  relations.  The  method  of  correlating  is 
discussed  in  the  opening  paragraphs  of  Part  III. 

CONCENTRATION  AND  INHIBITION 

Attention  has  been  regarded  as  simply  the  focussing  of 
consciousness,  which  resulted  in  a  consequent  brightening 
of  all  it  encompassed  without  directly  affecting  other  por¬ 
tions  of  consciousness.  It  has  also  been  regarded  as  the  proc¬ 
esses  by  which  all  other  parts  of  consciousness  are  obscured 
except  that  which  is  directly  engaged  in  perception  or  idea¬ 
tion.  There  is  surely  virtue  in  the  ‘golden  mean’  in  this 
case.  For  that  sharpening  between  the  area  of  clearness  and 
its  penumbra  of  obscurity,  which  was  mentioned  in  the  last 
chapter,  is  much  better  understood  if  we  consider  both  proc¬ 
esses  as  complementary  factors  in  attention. 


SOME  TYPES  OF  ATTENTION. 


17 


Probably  the  sharpness  with  which  the  clearness  area 
drops  away  into  the  obscurity  area  differs  with  different 
individuals.  The  introspection  of  Kiilpe,  however,  appeals  to 
me  as  being  in  close  concord  with  the  average  type  of  atten¬ 
tion.  He  sums  up  his  views: 

When  we  ask  how  the  degrees  of  consciousness  are  related  to  one  another 
we  find  not  one  uniform  graduation  from  the  highest  to  the  lowest,  but 
in  most  cases  a  fairly  sharp  line  of  distinction.  Certain  contents  stand 
at  the  level  of  clear  apprehension;  and  from  them  our  consciousness 
drops  away;  without  transition,  to  the  level  of  obscure  general  impression, 
above  which  the  other  contents  of  time  are  unable  to  rise.  And  the 
clearer  the  first  group,  the  more  indistinct  are  all  the  rest.’^ 

Physiological  psychology  gives  additional  weight  to  this 
view. 

Striking  effects  of  concentration  upon  any  object  are  frequent  in  the  ex¬ 
perience  of  everyone.  There  can  be  no  doubt  that  we  must  find  a  physio¬ 
logical  expression  for  this  singleness  of  the  object  of  attention  and  for  the 
power  of  one  object  to  banish  all  others  from  the  focus  of  consciousness. 
Translated  into  physiological  terms  it  means  that  only  one  of  the  percept¬ 
ual  systems  of  the  cortical  paths,  consisting  of  one  or  more  sub-systems  of 
sensory  areas  united  by  higher-level  paths,  can  be  active  at  any  one  mom¬ 
ent,  that  the  spread  of  the  nervous  excitement  through  one  such  system 
somehow  brings  about  the  cessation  of  activity  in  the  system  active  at 
the  previous  moment  and  prevents  the  activity  of  the  other  systems. 
Hence  we  need  not  seek  for  inhibitory  centers  in  the  cerebrum.  Each 
perceptual  system  of  arcs  is  an  inhibitory  center  for  every  other,  the 
activity  of  each  system  brings  about  as  a  collateral  effect  the  inhibition 
of  all  others.  .  .  Though  we  do  not  know  how  this  inhibition  is 

brought  about,  it  may  be  conceived  as  a  drainage  of  the  free  nervous 
energy  from  the  inhibited  to  the  inhibiting  system,  owing  to  the  latter 
becoming  for  the  moment  the  path  of  least  resistance.  There  is  evi¬ 
dence  that  similar  inhibitory  effects  are  excited  by  the  activity  of  any 
one  group  of  arcs  of  sensory  area  of  the  cortex  upon  other  arcs  of  the 
same  area,  especially  in  the  case  of  the  visual  area.^ 

Such  a  line  of  demarcation  between  the  fields  of  attention 
and  non-attention  enables  us  to  determine  with  considerable 

^Titchener,  E.  B.,  The  Psychology  of  Feeling  and  Attention,  p.  222. 

’McDougall,  W.,  Physiological  Psychology,  pp.  102,  103. 


i8 


H.  C.  McCOMAS. 


accuracy  the  ability  of  the  individual  to  concentrate  his  atten¬ 
tion,  From  the  testimony  of  those  whose  introspection 
resembles  that  of  Kiilpe,  the  more  intense  the  application  of 
the  attention,  the  plainer  appears  the  inverse  proportion  in 
clearness  between  the  attended  and  the  non-attended.  From 
the  results  of  such  work  as  McDougall’s  and  Sherrington’s, 
it  appears  that  the  more  alive  the  one  perceptual  system  of 
a  sensory  area  the  less  alert  is  its  neighbor.  The  concentra¬ 
tion  value,  therefore,  appears  in  the  relation  between  the 
included  and  the  excluded.  In  order  to  bring  out  individual 
differences  fairly  the  cards  containing  five  words  and  five 
colored  letters  or  figures  were  exposed  for  one  second  in  sev¬ 
eral  series  of  experiments  extending  over  five  weeks.  In  the 
first  series  the  subject  was  directed  to  concentrate  upon  the 
colored  objects  and  to  ignore  the  words  The  success  with 
which  this  was  accomplished  was  astonishing.  The  intro¬ 
spection  was  quite  uniform.  After  the  subjects  had  become 
accustomed  to  the  work  (and  not  till  then  were  any  of  their 
results  recorded)  the  ability  to  select  one  class  or  the  other 
was  very  marked.  For  all  subjects  I  have  exposed  the  same 
card  directing  his  attention  now  to  the  words  and  now  to  the 
colored  figures.  In  not  one  instance  did  the  subject  know  he 
had  observed  the  same  card — so  completely  were  the  objects, 
of  the  group  not  attended  to,  inhibited.  When  itis  remembered 
that  there  were  only  ten  objects  before  the  subject  and  that 
they  were  exposed  for  an  entire  second  the  phenomenon  of 
the  inhibition  of  half  of  them  becomes  impressively  significant. 
There  was,  however,  less  ability  to  get  clean-cut  results  when 
the  attention  was  directed  to  the  words.  The  reason  for  this 
is  the  greater  difficulty  in  attending  words  (compare  Tables 
I  and  II  for  Span).  It  is  far  easier  to  catch  a  color  when  the 
attention  is  upon  the  word-class  than  it  is  to  catch  a  word 
when  the  attention  is  directed  to  the  colors. 

The  table  below -represents  the  subjects  by  the  capital 
letters.  The  first  row  of  figures  represents  the  number  of 
words  which  entered  attention  when  the  concentration  was 
upon  the  colored  figures,  in  a  series  of  25  exposures  of  the 
usual  cards  containing  five  words  and  five  colored  figures. 


SOME  TYPES  OF  ATTENTION. 


19 


The  second  row  of  figures  represents  the  colors,  figures  and 
letters  which  entered  the  attention  when  the  concentration 
was  upon  the  words.  Twenty  exposures  were  made  for  this 
latter  series.  In  both  series  the  exposure  was  one  second. 
The  totals  give  the  correlation  ranking. 


TABLE  V 


Cor.  R . 

(4) 

(6) 

(9) 

(4) 

(7) 

(4) 

(2) 

(8) 

(l) 

(ro) 

Subjects..  .. 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

1st  Series. . . . 

2 

I 

I 

0 

0 

I 

2 

S 

2 

0 

2nd  Series... 

5 

8 

23 

7 

13 

6 

I 

10 

0 

28 

Totals . 

7 

9 

24 

7 

13 

7 

3 

IS 

2 

28 

I  cannot  believe  that  these  totals  tell  us  very  much  about 
the  ability  to  concentrate  and  inhibit  as  the  processes  norm¬ 
ally  operate.  For  it  would  appear  that  D  is  four  times 
as  apt  as  ‘K’  in  concentration,  whereas  ‘D’  was  suffering 
from  a  nervous  depression  and  could  hardly  keep  his  atten¬ 
tion  on  his  work  for  fifteen  minutes,  when  the  second  series  was 
taken.  While  ‘K’  was  in  excellent  condition,  a  scientist 
with  powers  of  concentration  trained  by  many  years  of 
exacting  work. 

The  figures  may  not  be  without  significance  for  a  study  of 
differences  which  relate  not  to  general  conditions  of  mental 
energy,  in  concentrating,  but  to  the  more  minute  cooperation 
of  the  ‘perceptual  arcs,’  which  need  not  be  a  series  of  acts  pro¬ 
tracted  over  a  considerable  period.  So  that  an  attention 
which  could  not  maintain  its  application  for  any  length  of 
time  could  still  do  a  very  clear-cut  piece  of  work  for  a  few 
seconds.  Thus  the  above  figures  tell  nothing  of  those  great 
types  of  attention  which  Stern  described.^ 

The  effort  to  elaborate  these  experiments  by  introducing 
distractions  was  also  rather  abortive  of  results  along  the  line 
of  individual  differences.  In  fact  the  work  with  distractions 
is  rather  misleading.^ 

'Stern,  L.  W.,  Ueber  Psychologie  der  individnellen  Diferenzen,  Kap.  viii. 

^Hamlin,  A.  J.,  Attention  and  Distraction,  Amer.  J.  of  Psychol.,  viii,  p.  3. 


20 


H.  C.  McCOMAS. 


With  one  subject  the  so-called  distraction  may  act  as  a 
stimulus,  with  another  it  may  be  very  disconcerting  when  he 
is  tired  and  nervous,  but  practically  ineffective  when  he  is 
at  his  best. 

In  one  set  of  tests  the  room  was  lighted  by  electricity  and 
for  the  cards  upon  which  the  usual  five  words  and  five  colored 
objects  were  displayed,  I  substituted  brilliantly  colored 
papers  of  just  the  same  proportion  as  the  cards  to  serve  as 
backgrounds.  There  was  sufficient  strangeness  in  the  change 
from  daylight  to  electric  light  to  make  the  exposure  seem  a 
little  different  from  usual,  and  so  to  discredit  any  shock  which 
the  first  colored  background  might  cause.  There  was  noth¬ 
ing,  however,  to  prevent  the  subject  from  detecting  the 
change  in  background  as  the  successive  exposures  were  made, 
for  even  in  the  electric  light  the  difference  between  the 
colored  backgrounds  was  startling,  when  they  were  placed 
together.  The  eye,  of  course,  had  to  traverse  the  colored 
papers  in  passing  from  one  word  to  another.  The  concen¬ 
tration  was  upon  words.  Table  VI,  below,  shows  the  total 
number  of  words  observed  in  the  seven  exposures  for  each 
subject  and  the  number  of  colored  squares,  letters  and  figures 
which  were  not  inhibited.  The  lowest  row  of  figures  shows 
which  background  was  first  detected  by  the  observer.  It  will 
be  noticed  that  the  first  four  backgrounds,  which  consisted 
of  yellow,  a  pea-green,  a  light  brown  and  a  light  blue,  were 
inhibited  by  all  subjects. 

Seven  exposures  were  given  with  the  usual  time,  one 
second;  the  usual  signal  of  one  and  one-half  seconds;  the 
usual  objects  were  presented,  in  fact  everything  was  care¬ 
fully  arranged  to  give  the  experiments  the  same  setting  as  the 
many  series  which  preceded  them. 


TABLE  VI 


SOME  TYPES  OF  ATTENTION. 


21 


It  would  not  be  safe  to  draw  any  far  reaching  conclusions 
from  seven  experiments.  It  must,  however,  be  obvious  from 
the  capacity  of  two  of  the  eleven  subjects  to  inhibit  the 
change  in  background  entirely  that  McDougall’s  surmise  as 
to  the  inhibitory  capacity  of  certain  perceptual  systems  in 
the  same  sensory  area  is  well  grounded. 

A  comparison  of  the  number  of  words  attended  in  these 
seven  experiments  and  seven  similar  experiments  under 
usual  conditions  shows  that  distraction  did  retard  many  of 
the  subjects.  This  a  number  of  them  felt  during  the  experi¬ 
ment,  but  none  of  them  assigned  the  influence  to  the  right 
cause.  Table  VII  shows  in  the  upper  row  of  figures  the 
number  of  words  attended  to  in  seven  experiments  with  no  dis¬ 
traction,  the  lower  row  of  figures  shows  the  totals  for  the 
seven  distraction  experiments. 


TABLE  VII 


B 

c 

D 

£ 

F 

G 

H 

j 

K 

L 

Cor.  R . 

(s) 

(7l) 

(l) 

(9) 

(7i) 

(2|) 

(10) 

(6) 

(4) 

(2^) 

Not 

used 

33 

29 

31 

25 

23 

26 

33 

26 

35 

29 

25 

24 

31 

23 

30 

25 

27 

25 

25 

24 

28 

32 

That  the  distraction  affected  the  several  subjects  dif¬ 
ferently  is  obvious.  (Rank  for  correlations  is  found  by  sub¬ 
tracting  the  lower  from  the  upper  row.) 

The  auditory  distraction  did  little  better  service  than  the 
visual.  This  is  to  be  expected.  However,  they  seemed  pref¬ 
erable  to  such  distractions  as  require  a  distribution  of  interest: 
for  in  such  work  it  is  hard  to  distinguish  between  distraction 
and  an  actual  division  of  attention.^ 

In  the  following  experiments  a  fire-alarm  bell  was  placed  on 
a  tin  box  within  eighteen  inches  of  the  subject’s  ear.  An 
electric  attachment  rang  a  bell  the  instant  the  shutter  of 

^Darlington,  T.  and  Talbot,  E.  B.  Methods  of  Distracting  the  Attention.  Amer. 
J .  of  Psychol.,  ix,  pp.  332-345.  Also,  Moyer,  F.  E.,  op.  cit.  viii,  p.  405. 


22 


H.  C.  McCOMAS. 


the  tachistoscope  opened,  and  broke  the  circuit  the  instant  it 
closed.  The  noise  was  violent,  almost  intolerable  to  the 
experimenter;  but  in  many  cases  it  was  not  found  objection¬ 
able  to  the  subject  engrossed  in  seeing  the  exposure.  Ten 
experiments  were  made  under  the  usual  conditions  of  time- 
exposure,  signal,  number  and  character  of  objects  exposed. 
The  following  table  shows  how  many  words  were  attended 
under  the  distraction  conditions  and  how  many  were  obtained 
in  a  series  of  experiments  without  distraction,  which  were 
chosen  at  random  from  another  series.  (Correlation-rank 
is  found  by  subtracting  the  Distraction  from  the  Non-dis¬ 
traction  row.) 

TABLE  VIII 


Cor.  R . 

(lo) 

(5) 

(4) 

(2) 

(9) 

(i) 

(8) 

(3) 

(6^) 

(6|) 

Subjects . 

A 

B 

C 

D 

E 

F 

G, 

H 

J 

K 

With  distraction . 

23 

39 

32 

33 

29 

38 

29 

39 

36 

30 

Without  distraction . 

33 

40 

32 

31 

37 

32 

36 

38 

41 

35 

It  appears  that  three  subjects  ‘D’,  ‘F’  and  ‘H’  did  better 
with  the  fire-alarm  than  without  it,  and  that  ‘C’  found  its 
presence  indifferent. 

If  such  an  experiment  could  be  varied  to  prevent  accommo¬ 
dation  on  the  part  of  the  subjects,  and  could  be  tried  a  great 
many  times  on  many  subjects  it  might  bring  out  an  interest¬ 
ing  typical  trait  in  some  subjects;  namely,  that  the  reinforce¬ 
ment  of  those  sensori-motor  arcs  engaged  in  perception  is 
conditioned  by  such  a  general  agitation.  Physiologically  it 
seems  to  point  to  typical  differences  in  the  ability  to  adjust 
the  great  afferent  currents  to  their  appropriate  motor  dis¬ 
charges,  and  so  brightening  the  vividness  and  the  clearness  of 
the  attention. 

A  rather  difficult  experiment  was  made  to  discover,  if 
possible,  what  differences  of  attention  might  appear  if  not 
perceptual  matter,  but  conceptual  matter,  were  material  for 
concentration  and  inhibition.  As  Professor  James  says: 


SOME  TYPES  OF  ATTENTION. 


23 


The  immediate  effects  of  attention  are  to  make  us  perceive,  conceive, 
distinguish,  remember  better  than  otherwise  we  could — both  more 
successive  things  and  each  thing  more  clearly  d 

So  the  facility  in  discriminating  and  retaining  may  be  con¬ 
sidered  an  indication  of  the  ability  to  concentrate.  Upon 
this  principle  a  series  of  fifteen  experiments  were  made.  Each 
card  was  exposed  three  seconds,  displaying  ten  words.  Five 
of  these  words  were  related  to  each  other.  Thus,  some  were 
names  of  parts  of  the  body,  or  parts  of  a  house,  articles  of 
furniture,  kinds  of  animals,  of  colors,  of  fruits,  etc.  All 
words  on  any  one  card  were  of  the  same  length.  Nothing  in 
the  appearance  of  a  word  would  indicate  whether  it  were  of 
the  class  to  be  attended  or  rejected.  They  were  also  thor¬ 
oughly  mixed  together  so  that  the  eye  had  to  traverse  the 
card  to  observe  all  those  of  a  certain  class.  Each  subject 
was  carefully  instructed  about  the  work  and  was  told  a  few 
seconds  before  the  shutter  opened  what  class  of  words  to  seek. 

The  introspection  was  of  a  very  similar  character  in  all 
cases  in  which  it  could  be  given.  Two  subjects  found  that 
they  could  not  recall  how  certain  words  were  retained  and 
others  inhibited.  It  would  seem  that  the  unsought  words 
are  perceived,  but  scarcely  recognized  as  of  the  unsought 
class,  and  instantly  dropped.  Probably  they  were  not  thrust 
from  attention,  but  their  memory  is  erased  by  the  incoming 
correct  word.  This  obliteration,  or  lack  of  assimilation,  when 
one  thing  follows  closely  upon  another  is  a  familiar  phe¬ 
nomenon  in  consciousness.  Enough  unanimity  appeared  in 
the  introspection  to  make  it  evident  that  the  eye  tarried 
longer  upon  the  desired  classes  than  upon  the  others.  This, 
too,  would  add  to  the  process  of  inhibiting.  In  a  very  large 
number  of  cases  the  words  of  the  unsought  class  would  not 
be  recognized  by  the  subject  when  read  to  him.  Indeed  many 
cards  were  shown  to  the  subjects  when  they  had  made  un¬ 
usually  good  records,  and  they  declared  that  they  could  not 
have  seen  the  words  of  the  unsought  class  for  not  a  vestige  of 
them  remained  in  consciousness. 


'James,  W.,  Psychology,  vol.  i,  p.  424. 


24 


H.  C.  McCOMAS. 


The  following  table  gives  the  total  number  of  words  at¬ 
tended  to  in  the  sought  classes  and  the  total  number  of  those 
attended  to  in  the  unsought  groups: 


TABLE  IX 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Words  correctly  attended . 

56 

61 

47 

59 

63 

56 

61 

64 

62 

55 

Words  which  should  have  been  inhibited . 

29 

16 

14 

12 

16 

18 

14 

21 

II 

9 

If  the  figures  for  the  words  which  were  correctly  attended 
to  by  each  subject  are  used  as  numerators  and  those  which 
should  have  been  inhibited,  as  denominators,  then  the  quo¬ 
tients  will  serve  for  correlation  ranking: 


A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

(10) 

(6) 

(7) 

(3) 

(5) 

(8) 

(4) 

(9) 

(2) 

(i) 

1-93 

3-8i 

■3-35 

4.91 

3-93 

3-II 

4-35 

3-05 

5-63 

6.  II 

The  above  tables  do  not  correlate  with  each  other  in  a 
single  instance.  (See  Correlation  Tables).  That  is,  each 
series  of  experiments  tells  a  different  story  from  the  others. 
So  no  conclusions  can  be  drawn  concerning  Concentration 
and  Inhibition  as  a  typical  mental  trait.  The  experiments 
show,  only,  marked  individual  differences  in  the  subjects 
under  the  special  conditions  of  each  experiment. 

The  Mean  Variations  in  the  experiments  on  Span  show 
individual  differences  in  the  constancy  of  attention.  It 
varies  in  its  efficiency  so  that  one  Mean  Variation  is  occasion¬ 
ally  half  again  as  large  as  another.  But  here,  again,  there  is 
absolutely  no  correlation  between  the  series.  The  fact  of 
variation  in  constancy  of  attention  must  be  recognized  along 
with  the  facts  of  variation  in  concentration,  though  they  may 
not  be  shown  in  their  relation  to  other  mental  traits. 


SOME  TYPES  OF  ATTENTION. 


25 


MOBILITY  OF  ATTENTION 

From  the  preceding  experiments  it  seems  clear  that  one 
class  of  exposures  is  easier  for  certain  subjects  to  attend  than 
others,  from  which  it  might  be  assumed  that  each  subject 
would  quickly  choose  his  best  class.  But  a  series  of  twenty- 
six  experiments,  which  were  performed  when  the  subjects 
had  been  working  with  the  tachistoscope  a  few  times,  reveals 
a  different  situation.  For  in  this  instance  the  subjects  were 
told  to  get  all  of  the  objects  presented,  if  possible.  They 
immediately  tried  to  attend  to  all  the  words  first  and  then  the 
colored  figures.  This  continued  throughout  the  series.  Sub¬ 
jects,  who  later  proved  that  colored  figures  were  more  easily 
obtainable  for  them,  in  this  early  experiment  stuck  to  the 
word  list  all  through.  The  explanation  is  not  far  to  seek. 
No  matter  what  class  of  objects  the  attention  is  considering 
it  is  more  natural  to  continue  in  that  class  than  to  shift  to 
any  other.  The  subjects  were  disposed  to  think  that  words 
were  the  easiest  to  attend  to  and  that  bias  started  them  on  the 
words  lists.  Once  started  upon  that  course  they  staid  in 
it  through  many  experiments. 

Introspectively,  it  seems  obvious  that  the  attention  stays 
upon  one  class  of  perceptions  in  preference  to  changing. 
Fechner  noted  this  many  years  ago.  It  has  often  been  corro¬ 
borated.  Every  day’s  experience  bears  witness.  The  turn¬ 
ing  from  the  newspaper  to  composing  a  letter,  the  changing 
of  attitude  in  passing  from  social  to  business  affairs,  the 
shifting  of  thought  in  passing  from  one  picture  to  another  in 
a  gallery;  these  and  a  host  of  experiences  give  evidence  of 
the  ‘inertia  of  attention.’^ 

The  explanation  of  this  lack  of  agility  in  attention  is  to  be 
sought  in  that  setting  of  consciousness  which  results  in  ad¬ 
justment  of  end  organs,  nervous  system  and  brain  paths,  to 
receive  the  sensation  expected.  Organic  adjustment,  then, 
and  ideational  preparation,  or  perception  are  concerned  in 
all  attentive  acts.  As  Wundt  says: 


^Titchener,  E.  B.,  Psychology  of  Feeling  and  AUention,  p.  246. 


26 


H.  C.  McCOMAS. 


Every  idea  takes  a  certain  time  to  penetrate  to  the  focus  of  conscious¬ 
ness.  And  during  this  time  we  always  find  in  ourselves  the  peculiar 
feeling  of  attention.  The  phenomena  show  that  an  adaptation  of  at¬ 
tention  to  the  impression  takes  place. 

Of  course  this  has  been  apparent  since  Wundt’s  experi¬ 
ments  upon  reaction-time  and  attention;  and  especially  since 
Miinsterberg’s  more  complicated  reaction  experiments  which 
showed  that  a  portion  of  consciousness  could  hold  itself  in 
readiness  to  do  certain  work  at  a  certain  time.  This  was  also 
evident  in  those  experiments  in  which  the  attention  was  pre¬ 
pared  to  get  a  certain  class  of  words  exclusive  of  others, 
(described  in  the  last  chapter.) 

Such  preparation  of  the  perceptual  and  conceptual  systems 
argues  that  certain  percepts  and  concepts  have  certain 
courses  through  consciousness,  that  there  are  definite  adjust¬ 
ments  in  the  complexes  of  sensori-motor  paths.  So  several 
of  my  subjects  would  say,  “Now  I  am  going  to  attend  to  this 
exposure  with  motor  attention,”  or  sometimes  “with  purely 
visual  attention.  ”  They  were  conscious  of  a  different  setting 
in  each  case.  For  the  colored  objects  the  attention  was 
largely  visual,  for  the  words  it  was  largely  motor, — in  many 
cases  the  subjects  repeated  the  words  sotto  voce.  The  figures 
and  letters  were  sometimes  attended  in  one  way  sometimes 
in  another.  The  point  is,  however,  that  for  the  different 
classes  of  objects,  different  kinds  of  acts  of  attention  were 
required.  The  change  from  one  class  to  another  demanded 
a  change  of  attentional  attitude.  This  we  shall  discuss  more 
fully  in  a  later  chapter.  It  is  sufficient  to  state  the  mere 
facts  in  the  matter. 

The  ability  of  the  attention  to  change  from  one  to  another 
class  shows  an  interesting  trait  in  the  control  of  the  attention. 
I'o  bring  this  out  clearly  I  arranged  fifteen  cards  with  colored 
geometrical  forms,  colored  figures  and  letters,  and  mono¬ 
syllabic  words.  These  were  placed  on  the  cards  in  miscel¬ 
laneous  positions  and  in  widely  varying  proportions.  It  was 
impossible  to  set  the  attention  for  any  one  class.  It  was  nec¬ 
essary  to  change  swiftly  from  class  to  class  in  order  to  obtain 
several  objects  in  the  one  second  exposure  allowed. 


SOME  TYPES  OF  ATTENTION. 


27 


The  table  shows  the  per  cent  of  objects  attended  to  the 
total  number  of  objects  displayed  in  each  series. 

TABLE  X 


Cor.  R . 

(d 

(3) 

(i) 

(8) 

(10) 

(7) 

(5) 

(6) 

(9) 

(4) 

Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

I 

K 

Percentage. . . 

56.4 

53-5 

S9-9 

42.4 

40.8 

44-5 

52.0 

48.5 

42.0 

52.1 

So  it  appears  that  between  ‘C’,  and  ‘E’  there  is  the  greatest 
difference  in  mobility  of  attention.  ‘C’  is  nearly  half  again 
as  apt  as  ‘E’  in  switching  the  attention  from  one  class  to 
another. 

Here,  as  in  Concentration,  we  must  remember  that  these  pro¬ 
cesses  which  occur  in  the  fraction  of  a  second  may  not  he  descrip¬ 
tive  of  all  those  activities  which  take  a  longer  time  and  are  more 
natural. 


CELERITY  OF  ATTENTION 

That  there  are  differences  in  the  rapidity  with  which  the 
central  processes  prepare  to  attend  certain  stimuli  is  amply 
demonstrated  by  those  experiments  in  reaction-time  where  a 
signal  is  given  at  varying  intervals  before  the  stimulus  is 
offered.  Some  individuals  react  better  to  a  two-second 
warning,  some  to  one  second;  the  average  preferring  one  and 
one-half  seconds.  So,  too,  we  have  seen  that  the  rates  of 
rapidity  of  attentional  acts  vary  greatly  in  different  readers. 
This  difference  was  thought  by  Dearborn  to  correlate  with 
breadth  of  span  in  attention,  ‘‘The  slow  readers  have  a  nar¬ 
rower  span  or  working  extent  of  attention.”^ 

It  seems  well  worth  comparing  some  experiments  which 
bring  out  the  subject’s  attitude  in  attending  to  a  number  of 
objects  in  quick  succession  and  a  series  which  indicates  a 
span  of  attention. 

The  following  experiments  were  performed  in  the  spring 
of  1908  with  different  subjects  from  those  whose  results  are 

‘Huey,  E.  B.,  The  Psychology  of  Reading,  p.  178. 


28 


H.  C.  McCOMAS. 


given  in  the  other  experiments.  Let  us  call  the  six  subjects 
‘X/  ‘Y/  ‘Z,’  ‘W,’  ‘A/  ‘A’  and  ‘D’  are  the  same  subjects 

represented  by  these  letters  in  the  other  experiments. 

To  bring  out  the  rapidity  with  which  the  attention  could 
pass  from  one  subject  to  another,  about  thirty  monosyllabic 
words,  thirty  black  geometrical  forms  and  thirty  small 
colored  squares  were  arranged  in  parallel  columns.  (A  dif¬ 
ferent  form  of  tachistoscope  was  used  from  that  described 
above.  It  allowed  a  very  large  field  of  exposure.)  The  sub¬ 
ject  was  told  to  count  the  objects  present  as  rapidly  as  possible. 
Three-second  exposures  were  given.  Then  he  was  directed  to 
write  down  as  many  objects  as  he  could  remember.  The  re¬ 
called  objects  were  remarkably  few  in  view  of  the  fact  that 
the  subjects  had  seen  these  same  words,  forms  and  colors 
in  other  experiments  many  times.  This  phenomenon  of  in¬ 
hibition  does  not  interest  us  here,  except  that  it  shows  the 
rapidity  with  which  the  counting  was  done.  The  remembred 
objects  were  totalled  and  presented  in  the  lower  row  of  figures 
in  table  A. 


TABLE  A 


Cor.  R . 

(i) 

(6) 

(3) 

(s) 

(2) 

(4) 

Subjects . 

X 

Y 

Z 

W 

A 

D 

Total  Objects  seen . 

77 

49 

54 

SI 

57 

52 

Total  objects  remembered . 

II 

9 

8 

14 

II 

7 

In  this  series  it  appears  that  X  is  half  again  as  quick  as  Y 
in  control  of  his  attention. 

This  experiment  was  supplemented  by  one  in  which  the 
subjects  counted  eighty  objects  and  their  time  of  observation 
was  carefully  taken.  The  following  table  shows  the  time 
required. 


TABLE  B 


COR.  R 

(i) 

(4) 

(3) 

(5) 

(2) 

(6) 

Subjects . 

X 

Y 

Z 

W 

A 

D 

Number  Seconds . 

i8 

25.6 

20 

26.8 

19.6 

27 

SOME  TYPES  OF  ATTENTION. 


29 


When  these  two  experiments  are  compared  they  both  tell 
the  same  story  as  we  shall  see  later. 

To  get  the  span  of  attention  a  photograph  was  exposed  for 
ten  seconds  and  the  subjects  wrote  down  all  the  details  they 
had  attended  to.  This  was  done  with  a  colored  picture  also. 
Then  a  series  of  exposures  of  three  seconds  was  made  for  ten 
cards  containing  eight  to  ten  colored  letters  and  geometrical 
forms.  The  following  table  gives  the  number  of  objects 
attended  to  by  each  subject  and  the  totals. 


TABLE  C 


COR.  R 

(1) 

(s) 

0) 

(4) 

(3) 

(6) 

Snhjert.s . 

X 

Y 

Z 

W 

A 

D 

Picture . 

54 

54 

87 

II 

29 

23 

66 

22 

18 

18 

Pnlnrerl  Picture . 

12 

19 

22 

18 

. 

55 

63 

76 

31 

Totals . 

195 

78 

118 

104 

116 

67 

In  addition  to  the  experiments  which  sought  to  determine 
the  span  of  attention  for  visual  perception  a  large  number 
of  trials  was  given  each  subject  for  auditory  span  (‘umfang’). 
An  instrument  clicked  uniformly  for  several  minutes.  The 
subject  was  instructed  to  group  the  clicks,  without  counting 
them,  in  the  largest  numbers  possible.  This  was  indicated 
by  the  subjects  raising  the  hand  or  tapping  with  a  pencil  when 
a  group  was  completed. 

The  following  table  shows  the  groups  to  represent  the 
subject’s  average  'span’.  The  figures  represent  the  number 
of  clicks  to  a  group. 

TABLE  D 


COR.  R 

(2) 

(6) 

(i) 

(4i) 

(3) 

(4i) 

Subjects . 

X 

Y 

Z 

W 

A 

D 

Groups . 

14 

4 

16 

8 

12 

8 

If  these  four  tables  are  correlated  according  to  Spearman’s 
'Footrule’  for  correlating,  which  is  explained  later,^  the 
following  correlations  appear. 


^See  page  47  for  explanation  of  the  ‘Footrule. 


3° 


H.  C.  McCOMAS. 


TABLES 

A 

B 

C 

D 

B . 

0.67 

0.67 

0.69 

C . 

0.48 

0.67 

0.56 

D . 

0.56 

0.69 

0.56 

The  probable  error  is  .176. 


From  these  figures  it  is  very  evident  that,  under  the  condi¬ 
tions  of  our  experimentation,  there  is  an  intimate  relation 
between  the  ability  to  shift  the  attention  from  one  object  to 
another  and  the  ability  to  grasp  a  large  number  of  the  objects. 
That  this  celerity  and  spanning  of  the  attention  are  not 
merely  a  peculiarity  of  attention  in  visual  perception  is 
proved  by  the  high  correlation  between  the  auditory  ‘um- 
fang’  and  the  results  for  celerity. 

The  results  of  some  experiments  designed  to  detect  the 
relation  between  span  and  association  time,  performed  at  the 
Princeton  Laboratory,  should  be  noted  here.  The  span  of 
attention  was  obtained  as  follows.  Cards  with  five  mono¬ 
syllabic  words  upon  them  were  exposed  for  two  seconds,  in 
Series  A ,  of  twenty  tests.  While  the  subject  was  attending  to 
the  words  a  series  of  sounds  (four  on  an  average  per  experi¬ 
ment)  were  made  by  striking  iron  on  wood,  on  tin,  on  a  gong, 
on  a  steel  rod,  by  a  buzz,  a  series  of  tones  on  steel  bars,  etc. 
The  subject  sought  to  attend  to  all  of  the  words  and  all  of  the 
different  sounds.  The  scheme  was  reversed  in  Series  B,  of 
twenty  experiments.  Here  the  subject  put  his  attention  pri¬ 
marily  upon  the  five  words  which  the  experimenter  read  aloud 
while  six  colors  or  colored  forms  passed  before  the  eyes  in  the 
second  during  the  reading.  Obviously,  the  attention  was 
strained  to  its  uttermost.  The  total  number  of  different 
sounds  heard  and  of  words  seen  in  the  first  series  for  the  two 
second  exposures  served  as  an  index  of  span  of  attention. 
The  second  series,  with  the  attention  primarily  upon  the 
words  spoken,  but  seeking  to  grasp  all  the  colors  and  figures 
seen,  supplements  the  first  series  and  gives  a  further  value  in 
its  totals  for  span. 

Each  of  these  series  was  compared  with  the  subjects’ 


SOME  TYPES  OF  ATTENTION. 


31 


association  time  for  one  word  and  for  four  words.  The  follow¬ 
ing  correlations  resulted. 


EXPERIMENTS  COMPARED 

COR.  COEF. 

PROB.  ERROR 

Span  in  Series  A  and  Ass.  Time  i  word . 

•334 

.  16 

Span  in  Series  A  and  Ass.  Time  4  words . 

•334 

.  16 

Span  in  Series  B  and  Ass.  Time  i  word . 

.429 

.  16 

Span  in  Series  B  and  Ass.  Time  4  words . 

no  correlation 

These  results  show  that  there  is  probably  a  connection  be¬ 
tween  the  ability  to  span  many  things  in  a  short  period  and 
the  ability  to  associate  quickly.  However,  such  a  correlation 
as  that  which  appears  between  the  span  of  attention  for 
spoken  words,  colored  objects,  etc.,  and  association  time  for 
one  word  is  very  suggestive,  when  considered  in  the  light  of 
the  results  for  span  and  quick  shifting  of  the  attention  in  per¬ 
ception.  Here  the  connection  lies  between  span  and  the 
quick  shifting  of  the  attention  in  conceptions. 

SOME  MEMORY  FACTORS  IN  ATTENTION 

A  very  noticeable  difference  appeared  among  the  subjects, 
throughout  the  entire  work,  in  the  way  in  which  the  objects 
attended  to  in  one  experiment  would  lie  dormant  in  the  mind 
and  would  be  reported  as  seen  in  a  later  exposure.  By  what 
unconscious  or  co-conscious  process  this  was  done  no  intro¬ 
spection  could  discover.  In  order  to  throw  some  light  upon 
the  phenomenon  four  sets  of  experiments  were  made.  In  the 
four  sets  the  same  cards  were  used.  These  contained  5  three- 
letter  words  and  five  colored  letters  or  figures.  The  exposure 
was  one  second.  In  each  set  the  subject  was  instructed  to 
attend  to  the  word-class  in  a  first  series,  and  later  to  attend  to  the 
color-class.  In  both  cases  he  was  to  perceive  as  many  objects 
of  the  class  attended  to  as  possible,  but  was  to  report  everything 
he  observed.  In  each  set  a  number  of  cards  were  repeated,  after 
the  lapse  of  a  certain  period,  to  discover  whether  any  details 
would  appear  in  the  second  exposure  which  were  not  reported 


32 


H.  C.  McCOMAS. 


in  the  first.  If  the  influence  of  an  exposure  lingered  in  the 
memory,  it  should,  of  course,  make  itself  evident  in  some 
difference  between  the  repeated  cards  and  those  which  were 
presented  for  the  first  time. 

Proceeding  upon  this  hypothesis,  about  twenty  cards  were 
repeated  after  the  lapse  of  a  week.  There  was  nothing  what¬ 
ever  in  the  results  of  any  subject  to  indicate  the  influence  of 
previous  experiments.  The  results  for  cards  never  seen  before 
were  quite  as  large  as  for  the  repeated  cards.  There  were  no 
introspective  results  to  indicate  a  continuance  of  the  previous 
objects  exposed  in  memory. 

It  was  impracticable  to  vary  the  number  of  days  between 
the  experiments,  so  the  next  set  of  trials  was  made  within 
an  hour’s  experimentation.  In  order  to  repeat  a  sufficient 
number  of  cards  in  the  hour  a  period  of  five  minutes  was  al¬ 
lowed  to  elapse  between  the  original  exposure  of  a  card 
and  its  repetition.  In  Table  I  five  minutes  elapsed  between 
the  first  and  the  second  exposures  of  the  cards.  In  Table 
II  there  was  a  two  minute  Intermission,  and  in  Table  III 
the  card  repeated  followed  immediately  upon  its  first  ex¬ 
posure.  The  figures  in  the  tables  are  found  by  subtract¬ 
ing  the  results  for  the  first  exposures  from  those  of  the 
repeated  exposures,  then  dividing  by  the  number  of  experi- 


TABLE  E 

TABLE  F 

TABLE  G 

w 

L 

w 

L 

w 

L 

TOTALS 

FOR 

SUBJECTS 

COR. 

RANKS 

A . 

o.  go 

0.  II 

-6.80 

I  .  22 

0-7S 

2.50 

4.68 

(6) 

B . 

0-75 

0.83 

0.80 

-0.25 

0.00 

1-50 

3  63 

(10) 

C . 

0.07 

0 

H 

1-33 

1.80 

0.60 

2.00 

7-30 

(2) 

D . 

O.S4 

1.44 

-0. 16 

0.50 

0.40 

1.80 

4-S2 

(7) 

E . 

0.44 

2 . 00 

0.40 

0. 20 

2.00 

1 . 80 

6.84 

(3) 

F . 

0.27 

1 .00 

0-33 

1-25 

0.25 

1 .80 

4.90 

(s) 

G . 

0.60 

0.62 

0.60 

1-33 

1 .00 

0. 20 

4-35 

(8) 

H . 

0-45 

0.33 

0.40 

0.00 

I -25 

I -75 

4.18 

(9) 

J . 

0. 10 

0.83 

0.00 

2.00 

0.7s 

1.30 

4.98 

(4) 

K . 

1 .00 

0,87 

-0. 16 

2.16 

1 . 70 

2.30 

7.87 

(i) 

0.512 

0-953 

0.274 

1 .021 

0.870 

j 

1 .69S1  Averages  (for  experi - 
j  ments) 

SOME  TYPES  OF  ATTENTION. 


33 


merits  per  subject.  Where  the  subject  averaged  less  per 
experiment  in  the  repeated  than  in  the  original  exposures 
the  loss  is  indicated  by  the  minus  sign.  (‘W’  =  word-class, 
‘L’=  letter-class). 

The  difference  between  the  subjects  is  very  evident  from 
the  tables;  there  is,  however,  no  correlation  between  the  sub¬ 
jects’  averages. 

In  noting  the  greater  increment  in  repetitions  for  the  word- 
class  than  for  the  letter-class  it  must  be  remembered  that 
the  Span  itself  is  greater  for  the  letter-class. 

The  most  instructive  feature  in  the  Tables  is  the  increase 
in  the  averages  for  the  repeated  exposures.  This  clearly 
proves  that  something  of  the  first  perceptions  of  the  cards 
lingered  in  memory  and  assisted  in  later  observations.  This 
influence  became  more  marked  as  the  time  between  the 
original  and  its  repetition  was  shortened.  In  the  repetitions 
which  followed  immediately  upon  the  originals  the  cards  were 
frequently  recognized  after  the  subject  had  seen  two  or  three 
objects,  but  in  the  series  of  repetitions  following  two  and  five 
minutes  after  the  originals,  recognition  was  comparatively 
infrequent. 

IDEATIONAL  TYPES 

The  terms  ‘Memory  Types,’  ‘Speech  Types’,  ‘Types  of 
Imagery’, have  been  used  very  frequently  to  point  out  charac¬ 
teristic  differences  in  the  way  in  which  different  classes  of 
individuals  imagine,  remember,  and  speak. 

In  both  physiological  and  theoretical  psychology  the 
‘division  of  labor’  in  the  mental  economy  is  constantly  em¬ 
phasized.  Experiments  are  often  performed  to  show  that 
memory  is  not  a  faculty  dealing  with  all  matter  in  the  same 
way,  but  that  it  divided  its  labor  among  visual,  motor, 
auditory  and  other  functions  of  the  mind.  The  work  upon 
aphasia  has  been  especially  enlightening. 

Internal  speech  is  a  revival  of  auditory,  visual  and  articulatory 
memories,  its  integrity  depends  upon  the  united  action  of  these  three 
centers;  but  the  one  which  is  the  most  highly  cultivated  is  revived  most 
vividly.^ 


^Collins,  J.,  The  Genesis  and  Dissolution  of  the  Faculty  of  Speech,  p.  62. 


34 


H.  C.  McCOMAS. 


Charcot  and  his  school  referred  to  those  who  were  the 
most  proficient  in  any  one  faculty  as  Visuels,’  ‘auditifs,’  and 
‘moteurs.’  Such  proficiency  comes  from  either  a  natural 
bent  or  an  adaptation  of  certain  faculties  to  certain  work. 
So  Baldwin  states: 

The  brain  is  a  series  of  centers  of  relatively  stable  dynamic  tension,  the 
various  associative  connections  among  these  centers  are  paths  of  less 
and  more  rather  than  least  and  most  resistance;  the  range  of  alternative 
judgment  is  occasionally  wide,  and  consequently  any  individual  has  his 
‘personal  equation  in  all  functions  as  complex  as  those  of  speech.  One 
man  is  a  ‘motor’,  a  second  a  ‘visual’,  a  third  an  ‘auditive’,  according 
as  one  or  another  of  the  extrinsic  causes  of  stimulation  suffices  to  release 
the  necessary  energy  into  his  motor-speech  center.”^ 

Not  only  are  the  activities  of  these  complexes,  that  give 
rise  to  expression,  conditioned  by  the  brain  paths  which  nature 
designed  as  the  highways  for  her  nervous  currents;  but,  also, 
by  those  byways  which  much  traffic  has  developed  into  high¬ 
ways.  Could  we  make  blue  prints  of  these  courses  our  charts 
would  show  some  strikingly  characteristic  differences.  And 
we  should  be  thoroughly  prepared  to  believe  that  the  conduct 
of  consciousness  in  general  is  obliged  to  adapt  itself  to  the 
conditions  of  its  thoroughfares.  Certainly  it  would  seem 
most  probable  that  the  “area  of  greatest  clearness”  in  con¬ 
sciousness  would  correlate  with  the  broader  and  more  evident 
mental  types.  We  find,  on  examining  consciousness,  that 
attention  is  not  a  fixed  thing,  a  faculty,  any  more  than  are 
memory  and  imagination. 

Yet  in  much  of  the  literature  of  late  years,  in  which  the  faculties  have 
been  scouted,  I  know  of  no  author  who  has  applied  his  own  criticisms 
consistently  to  the  attention.  Memory  on  the  other  hand  is  now  known 
to  be  a  function  of  the  content  remembered,  and  not  a  faculty  which 
takes  up  the  content  and  remembers  it.  So  we  have  no  longer  one 
memory,  but  many,  visual,  auditory,  motor  memories.  Yet  the  very 
same  thing  is  true  of  attention.  We  have  not  one  attention  but  many. 
Attention  is  a  function  of  content;  and  it  is  only  as  different  contents 

^Baldwin,  J.  M.,  Philos.  Rev.,  July,  1893,  p.  389. 


SOME  TYPES  OF  ATTENTION. 


35 


attended  overlap  and  repeat  one  another  that  they  have  somewhat  the 
same  function  in  attention.^ 

The  problem  before  us  is  to  discover  whether  these  idea¬ 
tional  differences  actually  do  affect  the  attention.  Does  a 
strongly  visual  type  naturally  select  a  different  class  of 
objects  to  attend  to  from  those  that  appeal  to  the  motor  type? 
Is  it  easier  for  those  perceptions  which  call  out  motor  activi¬ 
ties  to  be  attended  to  by  the  motor  type  than  by  the  visual? 
Do  such  differences  stand  out  clearly,  or  are  individuals  now 
of  one  and  now  of  another  type?  These  and  similar  problems 
are  now  before  us. 

It  will,  perhaps,  make  the  work  appear  clearer  if  the  experi¬ 
ments  upon  types  of  imagery  are  given  first.  It  will  enable 
us  to  detect  those  subjects  who  are  of  a  pronounced  type  and 
we  may  follow  their  results  through  the  other  experiments 
readily. 

Galton,  who  with  Titchener,  is  one  of  the  pathfinders  in 
mental  types,  prepared  a  table  of  questions  whose  answers 
indicated  the  subject’s  type.^  These  answers  were  graded 
according  to  the  degree  of  the  subject’s  realization  of  the 
imagery.  If  it  was  very  clear,  bright  and  distinct  it  headed 
the  series;  if  no  image  at  all  was  realized,  it  was  graded  zero. 
Between  these  extremes  were  seven  intermediary  grades.  In 
general,  I  followed  Gallon’s  scheme.  With  this  difference, 
however,  that  each  subject  graded  himself  according  to  the 
clearness  and  vividness  of  his  imagery  upon  a  scale  of  ten; 
zero  being  the  lowest  and  ten  the  highest.  The  questions 
were  read  to  the  subjects  and  any  misunderstandings  were 
made  clear.  Ample  time  was  allowed  for  deliberation.  The 
subject  considered  a  visual  image  first,  then  auditory,  then 
motor.  This  enabled  him  to  make  frequent  comparisons  of 
the  three  orders  and  allowed  for  a  separate  effort  and  judg¬ 
ment  for  each  question.  The  experiments  continued  through 
several  weeks.  This  tended  to  eliminate  minor  differences. 


^Baldwin,  J.  M.,  Mental  Development,  p.  468. 

^Gallon,  F.,  Inquiries  in  Human  Faculty. 

Titchener,  E.  B.,  Experimental  Psychology,  vol.  i,  chap,  xii; 


36 


H.  C.  McCOMAS. 


Subjects  varied  in  their  abilities  from  time  to  time.  Thus 
'K'  who  was  very  good  in  introspection  found  that  certain 
kinaesthetic  images  would  vary  perceptibly.  ‘D’  was  un¬ 
usually  poor  in  his  introspection;  so  inefficient,  in  fact,  that 
all  images  seemed  equally  distinct  whether  visual  or  gusta¬ 
tory,  auditory  or  olfactory.  I  have  inserted  his  results  for  a 
similar  series  of  experiments  performed  in  the  spring  of  1908, 
when  he  was  in  better  physical  and  mental  condition.  I 
found  that  the  memory  images  of  nearly  all  of  the  sub¬ 
jects  were  conditioned  by  the  memory  of  the  particular  per¬ 
son  or  the  particular  thing  remembered.  To  acquire  a  greater 
uniformity  I  selected  purely  imagery  matter  for  considera¬ 
tion. 

The  questions  were  for  the  auditory  imagery:  “How  clearly 
can  you  hear  a  harp  and  flute  playing  together;  a  trio,  of  two 
males  and  a  female  voice;  the  wind  blowing  through  trees  and 
sound  of  waves;  the  wind  blowing  a  tune;  the  songs  of  the 
Bedouin  Arabs;  a  conversation  in  Arabic;  the  cry  of  camels; 
the  scraping  of  a  file  on  a  violin;  the  sharpening  of  a  saw;  an 
artillery  bombardment.”  For  the  visual  were  asked:  “Can 
you  represent  to  your  mind  an  image  of  a  pyramid ;  can  you 
see  the  stones  clearly;  the  cracks  between  the  stones;  the  sand 
wastes  around  the  pyramid;  the  skies  above  it;  can  you 
imagine  a  cobweb  colored  red;  a  battlefield;  a  printed  page 
with  every  other  line  in  colored  ink ;  a  giraffe  reaching  for  the 
leaves  of  a  tree.  ”  For  the  motor  imagery  the  following  were 
asked:  “Can  you  represent  to  yourself  how  it  feels  to  write 
with  the  left  hand ;  to  wind  the  watch  with  left  hand ;  to  throw 
a  stone  with  the  hand  not  usually  used  in  throwing;  to  walk 
backward;  to  lift  the  hat  with  the  left  hand;  to  walk  through 
sand  shod  in  sandals;  to  do  an  oriental  dance;  to  waltz  and 
stoop  at  the  same  time;  to  gesticulate  like  the  deaf  and  dumb; 
to  ride  upon  a  camel.” 

When  a  subject  was  left-handed  or  ambi-dextrous  a  ques¬ 
tion  was  substituted  for  those  implying  a  normal  right- 
handed  practice. 

The  following  tables  represent  the  totals  of  the  grades  for 
the  three  orders.  Questions  were  not  asked  concerning  gus- 


SOME  TYPES  OF  ATTENTION. 


37 


tatory  or  olfactory  images  after  the  lists  for  strictly  memory 
images  were  discarded 


SUBJECTS 

TABLE  XI 

TABLE  XII 

TABLE  XIII 

VISUAL 

C.  R. 

(auditory) 

C.  R. 

(motor) 

C.  R. 

A . 

47 

(2) 

16 

(10) 

48 

(i) 

B . 

39 

(5) 

22 

(7) 

31 

(6) 

C . 

SO 

(i) 

41 

(2) 

37 

(3) 

D . 

27 

(9) 

49 

(i) 

33 

(5) 

E . 

41 

(4) 

37 

(3) 

25 

(10) 

F . 

23 

(10) 

25 

(5) 

27 

(8) 

G . 

30 

(8) 

18 

(8) 

34 

(4) 

H . 

38 

(6) 

33 

(4) 

30 

(7) 

J . 

45 

(3) 

17 

(9) 

41 

(2) 

K . 

36 

(7) 

23 

(6) 

26 

(9) 

These  tables  were  supplemented  by  a  series  of  experiments 
upon  associations,  to  discover  whether  the  visualizer  differed 
from  the  others  in  the  class  of  associations  or  in  his  association¬ 
time.  The  subjects  were  also  given  problems,  from  time  to 
time,  and  sought  to  introspect  upon  their  habits  of  mind  in 
solving  the  different  kinds  of  problems.  The  result  of  this 
work  is  not  given  as  it  did  not  prove  satisfactory.  The  above 
table,  which  is  based  upon  Titchener’s  method  gave  the 
clearest  results  obtained. 

VISUAL  PERCEPTION  AND  ATTENTION 

Our  perceptions  are  directed  by  the  heritage  of  brain  traits 
and  experiences.  When  these  mark  us  as  visualizers,  our 
perceptions  will  be  different  from  those  of  the  motor  types. 
In  the  perception  of  simple  color  there  is  very  little  motor 
activity.  Usually  there  is  no  disposition  to  pronounce  the 
name  of  the  color  or  shade  and  the  effort  to  recall  it  is  dis¬ 
tinctly  visual.  This  is  not  so  of  words.  Though  they,  too, 
are  sometimes  recalled  usually  and  perceived  as  visual 
objects  without  an  introspectively  perceptible  reaction,  when 
they  occur,  as  a  usual  experience  they  are  pronounced. 
Frequently  this  is  merely  an  internal  expression;  very  often 


38 


H.  C.  McCOMAS. 


it  results  in  lip-movement,  and  frequently  in  an  audible 
though  unconscious  articulation.  When  the  distractions  ac¬ 
companied  the  effort  to  perceive  the  largest  number  of  words 
possible,  there  was  a  very  marked  increase  in  motor  activity 
which  in  several  instances  resulted  in  the  subjects  speaking 
aloud  though  they  were  not  aware  of  it  at  the  time. 

In  the  following  experiment  there  were  exposed  fifteen 
cards  containing  colored  objects,  figures,  letters  and  three- 
lettered  words.  The  subject  was  told  to  select  as  many  ob¬ 
jects  as  possible  regardless  of  class.  The  exposures  were  one 
second.  Each  subject  had  had  a  long  and  varied  experience 
in  perceiving  the  classes  of  objects  presented  and  instinctively 
sought  that  which  was  easiest.  This  had  to  be  instinctive,  as 
each  card  varied  so  in  the  number  of  the  several  classes  of 
objects  and  the  time  was  so  short,  there  was  no  opportunity 
for  deliberation. 

In  the  following  table  the  per  cent  of  colors  obtained,  to 
total  number  of  colors,  is  given: 


TABLE  XIV 


Cor.  R . 

(4) 

(2) 

(i) 

(s) 

(10) 

(6) 

(81) 

(7) 

(3) 

Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Percents . 

42 

54 

S8 

30 

39 

26 

38 

30 

31 

The  high  figures  for  several  subjects  whom  we  saw  classed 
as  visualizers  in  the  ideational  type  experiments  is  practically 
explainable  by  the  fact  that  they  have  a  very  wide  span  of 
attention  for  the  color  classes,  as  may  be  seen  by  comparing 
their  results  for  ‘span,’  and  they  would  get  large  results  in 
such  cases.  We  shall  speak  of  this  later. 

Another  experiment  involving  color,  and  used  in  another 
connection,  will  assist  in  the  present  problem.  Twenty-six 
one-second  exposures  were  made  for  cards  containing  five 
words  and  five  colored  figures.  The  attention  was  upon  the 
colored  figures  primarily  and  the  subject  was  to  perceive  both 
figure  and  color  and  associate  them  together  in  his  report. 
This  involves  motor  as  well  as  visual  factors.  The  total  num- 


SOME  TYPES  OF  ATTENTION. 


39 


bers  of  associated  colors  and  figures  are  given  for  each 
subject  in  the  table  below: 


TABLE  XV 


Cor.  R . 

(i) 

(6) 

(3) 

(d 

(7) 

(8) 

(10) 

(5) 

Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

Totals . 

67 

28 

38 

39 

22 

21 

6 

30 

35 

The  totals  of  all  the  colors  perceived  out  of  a  possible  hun¬ 
dred  and  thirty  for  this  same  series  are  given  in  Table  XVI 


TABLE  XVI 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

T 

K 

Cor.  R . 

(i) 

(7) 

(2) 

(10) 

(3) 

(8) 

(9) 

(5I) 

(5i) 

(4) 

Total  Colors. 

92 

S3 

73 

35 

69 

42 

37 

54 

54 

67 

Another  experiment  was  made  in  which  five  colors  and  five 
geometrical  forms  were  presented  in  one  second  exposures. 
In  all  there  were  fourteen  exposures  with  the  attention  directed 
to  the  colors  which  were  simple  and  easily  perceived  and  re¬ 
called.  The  totals  for  the  colors  attended  are  as  follows: 


TABLE  XVII 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

(5) 

(7) 

(3i) 

(9) 

(6) 

(8) 

(10) 

(2) 

(i) 

(3i) 

Totals . 

62 

54 

63 

42 

55 

43 

27 

64 

66 

63 

One  of  the  most  interesting  of  these  experiments  was  per¬ 
formed  as  follows:  ten  brightly  colored  squares  were  exposed 
for  one  second,  the  subject  was  to  perceive  as  many  as 
possible  and  report.  After  fifty  such  exposures  were  made  five 
words  were  substituted  for  five  of  the  colored  squares.  The 
change  in  the  character  of  the  cards  was  not  announced  until 
subjects  discovered  it  themselves.  All  through  the  series  the 
the  instructions  were  to  get  all  that  it  is  possible  to  perceive 


40 


H.  C.  Me  COM  AS. 


no  matter  what  it  is.  The  result  was  that  some  subjects  con¬ 
tinued  to  get  colors  and  some  switched  over  to  the  words. 
There  was  probably  no  fatigue,  certainly  not  enough  to  count 
for  any  changes  in  the  direction  of  attention.  The  choice  of 
the  word  class  after  the  mometum  of  fifty  experiments  in 
the  color  class  is  indicative  of  a  natural  preference  for  the 
word  class. 

In  Table  XVIII  the  totals  for  the  colors  In  the  first  fifty 
experiments  are  given.  And  in  Table  XIX  the  per  cent  of 
colors  in  relation  to  total  perceptions  are  given.  (The  former 
is  Table  I  for  Span.) 

TABLE  XVIII 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

(4) 

(7) 

(i|) 

(9) 

(3) 

(10) 

(5I) 

(8) 

(5^) 

(T) 

Total  Colors . 

215 

205 

223 

161 

222 

141 

213 

199 

213 

223 

TABLE  XIX 


Subjects . 

A 

B 

C 

D 

E 

F 

H 

J 

K 

Cor.  R . 

Percent  of 

(i) 

(6) 

(4) 

(7) 

(5) 

(9) 

(10) 

(3) 

(8) 

(2) 

Colors . 

100 

57 

64 

44 

60 

30 

21 

69 

41 

85 

In  the  Table  of  Correlations  a  number  of  significant  corre¬ 
lations  appear  between  these  experiments  on  the  visual 
factors  in  attention.  Thus,  this  last  table  correlates  with 
tables  XV,  XVI  and  XVII.  The  meaning  of  this  will  be 
discussed  In  the  Conclusion;  here  It  Is  sufficient  to  call 
attention  to  the  fact  that  this  class  of  experiments  do  not 
correlate  with  a  single  one  of  the  experiments  in  the  next 
chapter  designed  to  bring  out  motor  factors  in  attention. 

MOTOR  FACTORS  IN  PERCEPTUAL  ATTENTION 

The  common  experience  was  that  the  words  called  forth 
the  ‘inner  speech.’  Each  one  was  pronounced.  At  times  the 
subject  would  pronounce  the  word  ‘Bug’  as  ‘Rug,’  and  when 


SOME  TYPES  OF  ATTENTION. 


41 


giving  his  report  would  repeat  it  as  he  pronounced  it  to  him¬ 
self,  but  it  would  seem  wrong  and  after  a  little  thought  he 
would  correct  it  by  visual  memory.  This  was  not  at  all 
common.  The  motor-auditory  process  usually  predominated, 
especially  in  memory.  For  it  was  a  universal  experience  that 
the  words  meant  nothing.  They  were  as  so  many  nonsense 
syllables  until  reported,  and  within  two  minutes  after  the 
report,  they  were  forgotten.  Without  the  co-operation  of  the 
'inner  expression.’  the  mere  visual  perception  of  the  words 
would  have  been  retained  very  poorly.  From  the  experi¬ 
ments  in  reading  it  would  seem  that  this  inner  speech  is  an 
incipient  movement.  It  does  not  effect  the  larger  or  chest 
muscles  perceptibly,  nor  does  it  produce  lip-movements  neces¬ 
sarily.  It  is  a  motor  activity  which  apparently  varies  as  the 
effort  to  make  the  perception  clear  and  strong  varies.  It  is 
marked  in  children  learning  to  read.  I  have  found  it  very 
pronounced  when  learning  a  strange  language,  but  it  is 
diminished  as  the  language  was  acquired.  Quantz  thought: 

It  is  a  specific  manifestation  of  the  general  psycho-physical  law  of  dyna- 
mogenesis  by  which  every  mental  state  tends  to  express  itself  in  muscu¬ 
lar  movement.* 

Our  interest  is  to  discover  whether  those  who  appear,  ac¬ 
cording  to  their  own  introspection,  to  be  clearly  motor  types 
are  influenced  in  the  direction  their  attention  instinctively 
takes,  in  the  effort  to  grasp  as  many  objects  as  their  span  will 
allow,  when  these  objects  call  out  more  or  less  of  the  motor 
activity. 

To  bring  this  out  a  series  of  fifteen  exposures  was  given  the 
subjects,  of  cards  containing  five  words  and  five  colored  letters, 
numbers  or  figures.  The  subjects  were  told  to  make  their 
own  selection  of  class  of  objects,  but  that  they  must  attend  to 
the  largest  number  possible  in  every  case.  In  Table  XX  the 
per  cent  of  words  to  the  total  number  of  objects  attended  to  is 
given. 


iQuantz,  J.  O.,  Psychol.  Rev.,  Mon.  Supp.,  vol.  ii,  No.  I.  See  also,  Philos.  Rev.,  ii., 
pp.  385-407;  Psychol.  Rev.,  1894,  pp.  441-453;  Yale  Studies,  Psychol.  Laboratory ,  ii.  p.  1 22. 


42 


H.  C.  McCOMAS. 


TABLE  XX 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

Percent  of 

(4) 

(i|) 

(8) 

(7) 

(9) 

(3) 

(i|) 

(5) 

(10) 

(6) 

Words . 

73 

8i 

6o 

62 

38 

74 

81 

72 

37 

65 

The  differences  in  the  results  for  the  subjects  are  sufficiently 
large  to  show  individual  preferences  which  may  be  taken  as 
indicative  of  mental  traits  as  affected  by  this  kind  of  experi¬ 
ment.  What  these  traits  are  does  not  appear,  for  this  series 
does  not  correlate  with  any  other  in  the  whole  Table  of 
Correlations. 

After  the  lapse  of  several  weeks  another  series  of  ex¬ 
posures  was  made  in  which  the  subjects  were  again  directed 
to  seek  that  class  which  is  the  easier  to  attend  to.  In  this  case 
there  were  five  words  and  five  colored  figures.  Twenty  one- 
second  exposures  were  made.  The  totals  for  word  are  given 
in  Table  XXL 


TABLE  XXI 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

(8) 

(10) 

(s§) 

(sl) 

(7) 

(3) 

(4) 

(9) 

(2) 

(i) 

Total  Words. 

60 

42 

72 

72 

69 

77 

76 

48 

8S 

86 

This  table  not  only  does  not  correlate  with  the  precediny 
experiment  of  like  character ;  but  it  also  fails  to  correlate  with 
any  of  the  others  except  those  represented  by  Table  IX  in 
Concentration  and  Inhibition.  From  this  correlation  it  would 
appear  that  the  disposition  to  turn  the  attention  to  words  in 
preference  to  colored  objects  and  the  ability  to  set  the  atten¬ 
tion  for  a  certain  class  of  words  and  to  inhibit  others,  are 
faculties  which  go  together. 

In  the  next  experiment  the  subjects  concentrated  upon  the 
words  only.  They  sought  to  inhibit  all  else.  The  purpose 
in  this  was  to  discover  whether  there  were  any  correlations 
between  the  ability  to  attend  to  the  word  class  and  the  other 


SOME  TYPES  OF  ATTENTION. 


43 


acts  of  attention  involving  motor  factors.  There  were  six 
three-letter  words  and  six  colored  figures  on  each  card. 
Twenty  exposures  of  one  second  each  were  made.  The  total 
number  of  words  attended  to  are  given  for  several  subjects  in 
Table  XXII. 

TABLE  XXII 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

(8) 

(2) 

(9) 

(7) 

(3) 

(10) 

(s) 

(4) 

(i) 

(6) 

Totals . 

66 

79 

64 

70 

78 

63 

75 

76 

82 

71 

Here,  the  only  correlation  is  with  the  experiments  for 
auditory  factors.  In  this  case  the  high  correlational  coefficient 
of  .51  indicates  a  relation  between  the  ability  to  concentrate 
upon  the  word-class  and  the  ability  to  attend  to  the  reading  of 
poetry  while  viewing  the  presentation  of  a  succession  of 
words.  (See  Table  XXVIII  in  chapter  on  Auditory  Factors.) 

Table  XVIII  of  the  last  chapter  may  be  used  to  find  the 
per  cents  of  those  who,  having  observed  colors  for  fifty  experi¬ 
ments  detected  the  wordsand  attended  to  them  when  they  were 
added  to  the  color-cards.  The  per  cent  of  words  to  total 
number  of  objects  seen, — when  the  words  were  added,  is  given 
in  Table  XXIII;  which  is  Table  XVIII  of  the  last  chapter 
reversed. 

TABLE  XXIII 


Subjects . 

A 

B 

C 

D 

E 

F 

G 

H 

J 

K 

Cor.  R . 

Percent  of 

(10) 

(5) 

(7) 

(4) 

(6) 

(2) 

(i) 

(8) 

(3) 

(9) 

Words . 

0 

43 

36 

56 

40 

70 

79 

31 

59 

15 

This  series  makes  two  interesting  and  important  correla¬ 
tions  with  the  experiments  on  Concentration.  The  first  cor¬ 
relation  is  with  the  experiments  which  were  designed  to  show 
the  subjects’  ability  to  concentrate  upon  words  or  colored 
objects  to  the  exclusion  of  other  classes  of  objects.  The  corre¬ 
lation  here  points  to  a  relation  between  an  aptitude  for  the 
word-class  and  the  ability  to  expend  the  attention  upon  one 


44 


H.  C.  McCOMAS. 


class  exclusively.  This  hints  at  what  has  already  been  noted, 
that  the  greater  activity  of  attention  required  by  the  word- 
class  demands  a  greater  effort;  and,  further,  appeals  to  those 
to  whom  this  kind  of  effort  is  natural  and  congenial.  The 
second  correlation  is  with  the  series  of  experiments  in  which 
the  subject  set  his  attention  for  a  certain  class  of  words  before 
the  exposure,  and  inhibited  all  of  the  other  classes.  Here  the 
faculty  of  turning  instinctively  to  the  word-class  and  the 
ability  to  set  the  attention  to  perceive  a  certain  class  of 
objects  appear  related.  This  may  mean  that  the  motor 
factors  which  make  it  easier  for  certain  subjects  to  attend  to  the 
word-class  also  make  it  easier  for  them  to  react  to  a  word  for 
which  they  are  seeking.  The  efficiency  then,  in  both  cases 
would  be  attributable  to  a  characteristic  readiness  of  motor 
response. 

AUDITORY  FACTORS  IN  PERCEPTUAL  ATTENTION  ' 

In  the  experiments  upon  aphasia  it  has  been  shown  that  the 
motor-auditory  complexes  play  as  important  a  role,  in  the 
processes  of  attention  which  accompany  speaking  and  reading, 
as  any  other.  The  inner  speech,  of  which  we  spoke  in  the 
last  chapter  is,  according  to  Huey,  a  combination  of  motor 
and  auditory  elements,  with  one  or  the  other  predominating 
according  to  the  subject’s  habitual  mode  of  imagining.’^  Huey 
and  Dodge  both  agree  that  the  motor  element  is  present  with 
those  who  auditize  in  reading  and  that  the  auditory  element 
is  present  with  those  who  motorize.  Huey  believes  that  these 
factors  may  not  be  so  prominently  present  with  visualizers. 

Now,  our  interest  is  to  learn  what  differences  characterize 
this  motor-auditory  type  in  their  attentional  processes.  They 
should  find  those  perceptions  which  can  be  the  more  readily 
dealt  with  by  the  habits  and  traits  of  their  motor-auditive 
systems  easier  to  bring  into  the  ‘area  of  greatest  clearness’ 
than  perceptions  which  do  not  call  out  such  reactions.  We 
should  be  justified,  in  the  light  of  experiments  previously 
described,  in  performing  a  series  of  experiments  in  which  the 


^Huey,  E.  B.,  The  Psychology  and  Pedagogy  of  Reading,  p.  120. 


SOME  TYPES  OF  ATTENTION. 


45 


competition  between  the  visual-motor  and  the  auditory-motor 
would  indicate  which  was  the  more  characteristic  of  the 
subject’s  type. 

Such  a  series  of  experiments  was  undertaken  as  follows; 
the  subject  sat  before  a  rotary  tachistoscope  in  which  several 
words  were  exposed  clearly  to  view  during  each  exposure. 
While  the  subjects  saw  and  read  these  words  two  lines  of  a 
poem  were  read  to  them.  The  attention  in  the  first  series 
of  experiments  was  directed  to  the  words,  but  the  subject 
was  also  told  to  retain  as  much  of  the  poetry  as  possible. 
When  the  report  was  given,  the  words  were  recited  first,  then 
the  poetry.  The  purpose  in  having  the  attention  thus 
divided,  rather  than  free  to  choose  either  class  of  perceptions, 
was  this;  it  is  impossible  to  present  auditory  and  visual  stimuli 
with  such  equality  that  the  one  does  not  obtain  some  advan¬ 
tage  over  the  other.  It  is  better  therefore,  to  give  an  advan¬ 
tage  first  to  one  and  then  to  the  other  by  distributing  the 
attention  consciously,  and  placing  its  emphasis  on  one  or  the 
other.  This  would  give  the  advantage  first  to  one  type  and 
then  to  the  other.  This  is  what  was  done.  After  a  series  of 
twenty-three  experiments  (Tables  XXVII  and  XXVIII)  in 
which  the  attention  was  primarily  upon  the  visual  impres¬ 
sions,  another  series  (Tables  XXV  and  XXVI)  of  twenty-two 
experiments  was  made  with  the  attention  directed  to  the 
auditory  impressions.  The  per  cent  of  words  to  the  total 
presented  is  given  in  the  left-hand  columns  of  both  tables. 
The  accuracy  with  which  the  poetry  was  attended  to  was  graded 
with  one  hundred  as  the  highest  count.  The  results  for  poetry 
appear  in  the  right-hand  columns.  Care  was  taken  that  the 
poetry  should  be  simple  and  the  lines  of  sufficient  brevity 
to  enable  each  subject  to  grasp  it  no  matter  how  inefficient 
he  might  be  in  memorizing  lines  read  aloud. 

In  Table  XXV  are  given  the  words  perceived  when  the 
attention  was  on  poetry,  and  in  Table  XXVI  the  grades  for 
the  amount  of  poetry  attended  in  the  same  series  are  given. 
In  Table  XXVII  appear  the  word  totals  when  the  attention 
was  directed  primarily  to  words,  and  in  Table  XXVIII  are 
the  grades  for  the  poetry  in  this  series.  Table  XXIV  gives 


46 


H.  C.  McCOMAS. 


the  sums  of  the  grades  for  the  poetry,  and  the  totals  for  the 
words  together,  for  each  subject.  These  indicate  the  span 
of  attention  for  visual  and  auditory  perceptions  combined. 


TABLES . 

XXV 

XXVI 

XXVII 

XXVIII 

XXIV 

WORDS 

C.R. 

POETRY 

C.R. 

WORDS 

C.R. 

POETRY 

C.R. 

TOTALS 

C.R. 

A . 

78.8 

(2) 

93-4 

(4) 

96.7 

(i) 

57-9 

(5) 

326.8 

(2) 

B . 

82.3 

(i) 

81.3 

(6) 

93-3 

(2) 

80.8 

(i) 

337-7 

(i) 

C . 

45-8 

(7) 

80.6 

(8) 

76.4 

(8) 

32.6 

(7) 

235-4 

(7§) 

D . 

65-3 

(3) 

48.0 

(9) 

7I-S 

(9) 

31  I 

(8) 

215-9 

(9) 

E . 

56.6 

(4) 

92.6 

(s) 

76.8 

(7) 

65.6 

(3) 

291 .6 

(4) 

F . 

34-2 

(9§) 

94-4 

(2I) 

82.4 

(5) 

24.4 

(10) 

235-4 

(7i) 

G . 

44-4 

(8) 

43-2 

(10) 

85-7 

(4) 

26.8 

(9) 

200.1 

(10) 

H . 

541 

(5) 

95-4 

(i) 

80.5 

(6) 

50.0 

(6) 

280.0 

(5) 

J . 

47-7 

(6) 

81.0 

(7) 

89.2 

(3) 

76.7 

(2) 

294.6 

(3) 

K . 

34-2 

(9§) 

94-4 

(2i) 

7^-4 

(10) 

58.0 

(4) 

258.0 

(6) 

The  most  obvious  result  of  these  tests  is  that  there  are  very 
wide  differences  in  the  abilities  of  the  several  subjects  to 
attend  to  what  is  being  heard  and  what  is  being  seen  at  the 
same  time.  The  order  of  ability  to  ‘span’  both  visual  and 
auditory  presentations  clearly  corresponds  with  the  order 
found  for  span  when  the  perceptions  were  visual  and  visual- 
motor.  This  appears  in  several  correlations  between  the 
Tables  for  Span  and  those  above,  (see  Table  of  Significant 
Correlations).  This  correlating  of  the  visual,  motor  and 
auditory  factors  in  attention  confirms  what  was  said  in  the 
chapter  on  Celerity,  that  the  experiments  measure  actual 
differences  in  the  attentional  processes,  and  not  mere  eccen¬ 
tricities  of  perception. 

The  primary  question  in  this  chapter  is;  do  those  who  have 
the  clearer  auditory  imagination  give  any  evidence  of  this 
trait  when  the  attention  is  directed  to  auditory  perceptions. 
The  answer  is  in  the  high  correlation  coefficient  for  Table 
XXIV  above,  and  Table  XII,  Ideational  Types,  (Auditory 
Type.)  This  correlation  is  the  highest  the  Auditory  Type 
yields.  Indeed  there  is  but  one  other  correlation  with 
auditory  type  in  the  entire  work.  There  is,  however,  no 


SOME  TYPES  OF  ATTENTION. 


47 


correlation  between  Auditory  Type  and  any  of  the  other 
Tables  for  Auditory  Factors. 

The  Visual  Type  has  as  high  a  correlation  with  the  Table 
XXIII,  above,  as  does  the  Auditory.  But  it  must  be  remem¬ 
bered  that  the  visualizer  has  a  broad  span,  as  numerous 
correlations  throughout  have  shown,  and  it  is  to  be  expected 
that  his  results  in  these  experiments  would  total  high.  The 
Visual  Type,  also,  shows  a  correlation  with  the  ability  to  per¬ 
ceive  words  when  the  attention  is  engaged  in  hearing  words. 
Both  of  these  aptitudes  may  be  due  to  the  facility  with  which 
the  visualizer  catches  the  objects  of  visual  perception  leaving 
other  energies  of  the  attention  free  to  engage  with  other 
things.  This  the  Motor  Type  could  not  do,  for  his  sole  corre¬ 
lation  with  these  tables  is  in  the  ability  to  attend  the  word 
series  when  the  attention  was  upon  the  words,  primarily; 
which  bears  out  what  has  been  observed  before,  that  when 
the  words  are  attended  with  a  motor  reaction,  as  they  usually 
are  by  the  Motor  Type,  there  is  little  attentional  energy  left 
to  be  occupied  with  aught  else. 

Part  III.  Correlations 

In  the  present  chapter  we  shall  compare  the  entire  list  of 
experiments  to  discover  what  traits  of  attention  are  related. 
The  most  satisfactory  way  to  accomplish  this  is  by  pre¬ 
senting  the  results  in  one  great  correlation  table.  The  sig¬ 
nificant  correlations  in  this  table  are  presented  in  a  smaller 
table  in  order  that  they  may  be  more  readily  seen  and  studied. 
(See  tables  at  end  of  monograph.)  After  considering  a  num¬ 
ber  of  methods  for  the  comparing  the  results  of  the  experi¬ 
ments,  Spearman’s  ‘Footrule’  for  measuring  correlations  was 
adopted.  The  method  is  explained  in  full  in  the  article  en¬ 
titled  Footrule  for  Measuring  Correlation,  by  C.  Spear¬ 
man,  in  the  British  Journal  of  Psychology,  vol.  ii,  pp.  89-108. 
Briefly,  the  method  is  this:  the  subjects  are  arranged  in  the 
order  of  their  ability  for  two  sets  of  experiments;  for  example, 
the  two  experiments  recorded  with  their  results  in  Table  XXI 
in  the  chapter  on  Motor  Factors  and  Table  IX  in  the  chapter 


48 


H.  C.  McCOMAS. 


on  Concentration.  The  second  series  of  results  is  compared 
with  the  first  and  the  sum  of  the  gains  in  rank  for  the  several 
subjects  carefully  noted.  Thus: 


SUBJECTS 

MOTOR  FACTORS 

CONCENTRATION 

SUM  OF  GAINS 

Table  XXI 

Table  IX 

A . 

8 

10 

2 

B . 

10 

6 

C . 

sl 

7 

15 

D . 

5i 

3 

E . 

7 

5 

F . 

3 

8 

5 

G . 

4 

4 

H . 

9 

9 

J . 

2 

2 

K . 

I 

I 

Total . 

00 

The  sum  of  gains  in  rank  is  denoted  by  Sg  in  the  follow¬ 
ing  formula. 

Let  the  2g  to  be  expected  on  an  average,  for  mere  chance 

*■”  I 

be  denoted  by  M;  this  amounts  to  -  when  n  is  the  num- 

6 

ber  of  cases  in  each  series.  (For  proof  see  page  105  of  Spear- 

man’s  article).  Then  the  coefficient,  say  R=  i - . 

M 

10^  — I 

In  the  present  experiments  n  =  10.  So  that  M  =  — g —  = 

—  =  16.  s.  Then  the  correlation  for  the  above  tables  will  be 
6  ^ 

i?  =  i— —  =  1—  =  0.4849. 

M  16.5  ^ 

It  must  be  remembered  that  in  this  (and  in  almost  every)  probability 
formula,  any  experimental  result  such  as  R  has  no  scientific  significance 
— except  negatively — unless  it  be  at  least  twice  as  great  as  its  probable 
error;  for  otherwise  it  is  almost  as  likely  as  not  to  be  a  chance  coincidence. 
To  be  fairly  good  evidence,  the  R  must  be  over  three  times  greater  than 
its  probable  error  {Ibid.,  p.  96). 


SOME  TYPES  OF  ATTENTION. 


49 


In  the  following  tables  the  decimal  is  carried  only  to  the 
second  place  as  the  numbers  are  sufficiently  far  apart  to  make 
decimals  of  the  second  and  third  places  unnecessary. 

The  Probable  Error  may  be  taken  with  sufficient  nearness 

as  being  ( For  proof  see  p.  The  Probable  Error 

V  n 

in  the  following  Table  is: 

243  =0.136. 

V 10  3-i62 

In  this  way  we  learn  that  our  correlation  in  the  above 
tables  is  just  about  large  enough  to  be  beyond  reasonable 
suspicion  of  chance  coincidence. 

Positive  correlations  point  out  relationships  which  actually 
exist  between  two  mental  traits.  The  negative  correlations 
show  that  the  traits  compared  do  not  exist  in  conjunction, 
but  that  where  we  find  one  the  other  will  be  absent.  Nega¬ 
tive  correlations  are  of  value  in  corroborating,  or  contradict¬ 
ing  the  positive. 

In  the  correlation  formula  used  a  large  negative  correla¬ 
tion  may  be  changed  to  a  positive  if  one  of  the  two  series 
being  compared  is  inverted.  Thus,  if  the  sum  of  the  gains 
in  the  second  of  the  two  series  totals  11.5  the  correlational 
coefficient  will  be  0.30.  If  the  order  of  this  second  series  were 
reversed  the  sum  of  the  gains  will  be  19.55  and  its  R  is  .18. 

The  table  of  significant  correlations  contains  all  those  posi¬ 
tive  correlations  which  are  above  twice  the  probable  error. 
In  the  groups  discussed  below  only  those  correlations  which 
are  above  three  times  this  probable  error  are  considered ;  for, 
as  Spearman  points  out,  a  low  correlation  is  not  trustworthy. 
It  is  important,  however,  if  it  occurs  frequently.  For  that 
reason  the  smaller  figures  appear  in  the  positive  correlation 
table.  In  arranging  the  correlation  results,  below,  each 
experiment  is  given  and  its  correlations  with  the  others. 
The  correlational  coefficient  is  given  in  parentheses  and  the 
experiment  is  briefly  described  with  an  abbreviated  reference 
to  the  chapter  and  table  where  it  is  described  in  detail. 


50 


H.  C.  McCOMAS. 


Span 

Totals  for  all  experiments  in  Span  (Span  IV) : 

Correlate  (0.54)  with  Visual  Imagination  (Ideat.  Types  XI). 
Correlate  (0.57)  with  Ability  in  Attending  color-class  (Vis.  Per.  XVI). 
Correlate  (0.42)  with  Adherence  to  color-class  (Vis.  Per.  XIX). 
Span  of  Attention  for  Colored  Objects  (Span  I): 

Correlate  (0.63)  with  Instinctive  Selection  of  color-class  (Vis. 
Per.  XIV). 

Correlate  (0.54)  with  Ability  in  Attending  color-class  (Vis.  Per. 
XVI). 

Correlate  (0.45)  with  Retention  in  Fringe  of  Attention  of  former 
objects  seen  (Mem.  Factors). 

Correlate  (0.45)  with  Visual  Imagination  (Ideat.  Types  XI). 

Span  of  attention  for  Colored  Letters  And  Numbers  (Span  III) : 

Correlate  (0.66)  with  Ability  in  Attending  color-class  (Vis.  Per. 
XVI). 

Correlates  (0.45)  with  Visual  Imagination  (Ideat.  Types  XI). 
Correlations  between  the  several  Experiments  upon  Span. 

Span  for  colored  objects  (Span  I)  correlates  with  span  for  colored 
letters  and  figures,  (Span  III)  and  the  Totals  for  all  Span 
Experiments  (Span  IV),  Correlate  (63)  with  Span  I,  (42)  with 
Span  II  and  (0.78)  with  Span  III; 

Concentration  and  Inhibition 

Ability  to  concentrate  upon  one  class  of  Objects  (Concent.,  etc.  V). 

Correlate  (0.51)  Preference  for  word-class  (Motor  Fac.  XXIII). 
Ability  to  concentrate  when  objects  are  upon  Colored  Backgrounds 
(Concent.  VII). 

Correlate  (0.45)  Ability  in  color-class  (Vis.  Per.  XVII). 

Ability  to  concentrate  upon  words  of  a  certain  Class  (Concent,  etc.  IX). 
Correlate  (0.48)  Instinctive  Selection  of  the  word-class  (Motor 
Fac.  XXI). 

Ideational  Types 

Visual  Imagination  (Ideat.  Types  XI) ; 

Correlate  (0.57)  with  Ability  in  Attending  color-class  (Vis.  Per. 
XVI). 

Correlate  (0.51)  with  Ability  to  Associate  colors  with  their  objects 
(Vis.  Per.  XV). 


SOME  TYPES  OF  ATTENTION. 


51 


Correlate  (0.42)  with  Instinctive  Selection  of  the  color-class  (Vis. 
Per.  XIV). 

Correlate  (0.48)  with  Span  of  Auditory  Attention  (Aud.  Factors 
XXIV). 

Auditory  Imagination  (Ideat.  Types  XII). 

Correlate  (0.48)  with  Span  of  Auditory  Attention  (Aud.  Factors 
XXIV). 

Correlate  (0.42)  Concentration  of  Attention  during  Fire-alarm 
distraction  (Concent,  etc.  VIII). 

Motor  Imagination  (Ideat.  Types  III). 

Correlate  (0.45)  with  Ability  to  associate  colors  with  their  objects 
(Vis.  Per.  XV). 


Motor  Factors,  etc. 

Ability  in  Attending  the  word-class  (Motor  Fac.  XXII). 

Correlate  (0.51)  with  ability  to  attend  Poetry  read  while  concen¬ 
trating  primarily  on  words  seen  (Aud.  XXVIII). 

Ability  in  attending  the  word-class  (Motor  Fac.  XXI). 

Correlate  (0.42)  with  memory  experiments. 


Visual  Perception,  etc. 

Instinctive  selection  of  color-class  (Vis.  Per.  XIV). 

Correlate  (0.45)  with  the  ability  to  shift  the  attention  from  one 
class  to  another  (Mob.  X). 

Ability  in  Attending  the  color-class  (Vis.  Per.  XVI)  correlates. 

(0.42)  Totals  for  Auditory  work  (Aud.  XXIV). 

The  Adherence  to  the  color-class  when  the  word  is  introduced  (Vis.  Per. 
XIX). 

Correlate  (0.42)  with  Auditory  spanning  of  attention.  (Aud.  XXVI) 

The  Experiments  upon  Visual  Perception  and  Attention 
correlate  among  themselves  as  follows.  The  ability  to  attend 
the  color-class  correlates  (0.48)  with  the  adherence  to  the 
color-class  when  the  word-class  is  also  introduced.  The  two 
similar  experiments  upon  ability  to  attend  the  color-class 
correlate  (0.42)  with  each  other. 


52 


H.  C.  McCOMAS. 


Auditory  Factors  in  Perceptual  Attention 

The  majority  of  correlations  between  the  auditory  experi¬ 
ments  and  the  other  experiments  appear  in  the  above  groups. 
It  remains  for  this  group  to  note  simply  the  correlations  of 
these  experiments  with  each  other.  The  totals  for  Span  in 
all  the  auditory  work  (Aud.  XXIV)  correlate  (o.6o)  with 
the  ability  to  attend  to  poetry  read  when  the  attention  is  pri¬ 
marily  upon  words  seen  (Aud.  XXVIII),  and  the  totals,  also 
correlate(o.48)  with  the  ability  to  attend  the  words  seen  in 
the  same  tests  (Aud.  XXV).  It  is  also  noteworthy  that  the 
totals  for  these  experiments  give  a  ranking  which  correlates 
with  three  out  of  the  four  of  the  constituent  experiments. 

From  the  above  correlations  it  may  be  inferred  that  the 
observer  who  is  broad-spanned  for  all  classes  of  objects  seen 
is  of  the  visual  type  of  imagination.  Further,  he  shows  a 
preference  and  an  unique  ability  in  attending  to  the  color- 
class  of  objects.  The  ability  to  attend  to  a  large  number  of 
colored  objects  is  coupled  with  an  instinctive  preference  for 
that  class  and  is  related  to  the  faculty  of  carrying  the  im¬ 
pression  of  former  observations  in  the  fringe  of  attention. 

The  results  for  concentration  are  rather  scattering.  The 
knack  of  inhibiting  the  distraction  of  a  colored  background  is 
related  to  special  ability  in  attending  to  the  color-class.  Why 
this  should  be  so  is  hard  to  understand.  The  ability  to  con¬ 
centrate  upon  the  word-class  and  to  ‘set  the  attention’  for  a 
certain  class  of  words  both  seem  to  be  connected  with  a 
fondness  for  the  word-class.  This  may  be  due  to  a  motor 
setting  of  the  attention. 

The  Ideational  Types  are  most  instructive  in  the  relation 
the  Visual  Imagination  sustains  to  visual  perception.  There 
can  be  little  doubt  that  the  visualizer  is  more  successful  in  at¬ 
tending  to  the  color  class  than  to  the  words.  It  is  curious  that 
the  visualizer  also  does  well  in  the  auditory  work.  The  very 
few  correlations  that  the  Auditory  Type  of  Imagination  makes 
renders  its  correlation  with  span  for  auditory  work  significant. 
This  correlational  value  with  auditory  span  is  the  same  for 
the  visualizer,  and  it  must  be  remembered  that  the  attention 


SOME  TYPES  OF  ATTENTION. 


53 


was  directed  to  visual  as  well  as  auditory  perceptions  in  the 
auditory  work.  An  unusual  correlation  is  that  between  the 
ability  to  span  visual  and  auditory  perceptions  synchron¬ 
ously  and  the  ability  to  inhibit  auditory  distractions.  The 
connection  between  the  motor  type  of  imagery  and  the 
ability  to  connect  a  color  with  the  object  upon  which  the 
color  appeared  would  seem  to  imply  a  relation  between  visual 
and  motor  retention  of  objects  observed. 

The  connection  between  the  faculty  for  attending  to  the 
word-class  and  for  attending  to  poetry  while  viewing  words 
may  point  to  a  motor  repetition  of  the  verses  which  would  be 
easier  for  the  moteur  than  the  visualizer.  Ability  in  the 
word-class  correlates  with  the  holding  of  objects  previously 
observed  in  the  fringe  of  attention. 

In  the  experiments  upon  Visual  Perception  and  Attention 
the  most  significant  fact  is  the  correlation  between  the  dif¬ 
ferent  experiments  in  this  same  class.  It  is  evident  that 
there  -is  some  underlying  trait  of  attention  which  appears  in 
these  tests.  It  is  probably  an  ability  to  attend,  remember  and 
imagine  in  visual  terms  better  than  in  others. 

The  auditory-visual  experiments  show  rather  scattering 
correlations.  Their  correlations  among  themselves  show  they 
point  in  one  general  direction.  The  lower  correlations  show 
an  interesting  relation  to  span  for  visual  work. 

A  comparison  of  the  Tables  of  Significant  Correlations  and 
Negative  Correlations  is  one  of  the  best  indications  that  the 
experiments  actually  point  out  typical  traits  in  Attention  and 
that  the  results  are  not  accidental. 

If  the  Significant  Correlations  were  in  about  the  same  pro¬ 
portion  as  the  Negative  for  each  set  of  experiments,  it  would 
be  apparent  that  the  whole  work  is  unreliable,  and  the  results 
fortuituous.  This  is  not  the  case.  Following  the  correlations 
for  Span  across  the  Table  it  appears  that  the  Positive  and 
Negative  correlations,  which  are  significant,  occur  in  the  fol¬ 
lowing  proportions;  3  :  o;  2  :  6;  o  :  o;  3  :  o;  10  :  i ;  o  :  7 ; 

5  •'  I ;  2  :  o.  Those  for  Visual  Perception  are  much  more 
striking;  8:o;o:i3;7:o;i;i.  The  negative  correlations 
support  the  positive  in  nearly  every  case.  The  results  for 


54 


H.  C.  McCOMAS. 


Concentration  and  Inhibition  are,  as  might  be  expected, 
the  least  reliable. 

The  negative  correlation  between  concentration  experi¬ 
ments  and  Span  is  a  further  support  to  what  has  been  found 
before,  that  span  and  concentration  do  not  seem  to  be  related. 

The  many  negative  correlations  between  Span  and  Motor 
Factors  show  conclusively  that  the  motor  element  in  attend¬ 
ing  to  the  word-class  is  a  feature  of  attention  which  does 
not  go  with  Span. 

It  is  interesting  to  note  that  the  only  positive  correlation 
Mobility  makes  is  with  Instinctive  preference  for  color-class 
and  the  only  high  negative  is  with  Preference  for  the  word- 
class. 

The  five  negative  correlations  between  Visual  and  Audi¬ 
tory  Types  and  the  three  experiments  on  Motor  Factors  are 
not  high  enough  to  carry  much  weight  but  they  are  suggestive 
in  showing  a  negative  relation  between  Motor  Factors  and 
the  Visual  and  the  Auditory  Types  but  not  the  Motor  Type. 

The  many  negative  correlations  between  the  experiments 
with  Motor  Factors  and  in  Visual  Perception  show  again, 
that  the  series  of  experiments  affected  attention  in  charac¬ 
teristically  different  ways. 

In  summing  up  the  results  of  the  Negative  Correlations  it 
may  be  said  that  they  corroborate  the  findings  of  the  Posi¬ 
tive  Correlations,  but  do  not  add  to  our  information  materi¬ 
ally.  A  casual  comparison  of  the  two  Tables  shows  this 
clearly.  A  more  exact  study  brings  to  light  the  fact,  noted 
earlier  in  the  text,  that  those  experiments  whose  results  were 
not  entirely  clear  (such  as  the  work  in  Concentration)  have  a 
more  even  proportion  of  positive  and  negative  correlations 
than  do  the  experiments  upon  Span,  Types,  Motor  and  Visual 
Factors,  etc.  In  the  latter  the  proportions  for  the  two  classes 
of  correlation  are  thoroughly  consistent  and  convincing. 

CONCLUSION 

From  the  foregoing  correlations  and  discussions  the  follow¬ 
ing  conclusions  are  deduced,  concerning  Types  of  Attention, 


SOME  TYPES  OF  ATTENTION. 


55 


under  the  conditions  of  experimentation  described  in  the  pre¬ 
ceding  chapters. 

1.  There  are  broad  and  narrow  spanned  types  of  atten- 
tional  activity.  The  broad  spanned  type  for  visual  per¬ 
ceptions  is  also  broad  spanned  for  auditory  perceptions  (um- 
fang). 

2.  There  is  also  a  type  of  attention  which  is  alert,  active, 
under  quick  control;  and  there  is  a  type  which  moves  slug¬ 
gishly.  The  former  is  broad  spanned. 

3.  The  ability  to  concentrate  and  inhibit  does  not  appear 
in  close  relation  with  any  other  marked  traits  of  attention. 
This  ability  varies  in  individuals  but  not  in  a  manner  which 
gives  evidence  of  type. 

4.  The  dexterity  or  suppleness  in  control  of  attention  is 
another  feature  which  cannot  be  classed  as  a  Type. 

5.  The  impressions  which  catch  in  the  ‘Fringe’  of  atten¬ 
tion  and  later  enter  the  ‘Clearness  Area,’  vary  characteris¬ 
tically  with  individuals.  The  type  most  susceptible  to  this 
experience  is  also  broad  spanned. 

6.  The  Visualizer  is  broad  spanned  for  both  visual  and 
auditory  perceptions. 

7.  The  ‘Auditif’  shows  his  attentional  type  in  the  ability 
to  inhibit  sound  and  in  the  breadth  of  span  for  visual  and 
auditory  impressions  presented  synchronously. 

8.  The  Motor  Type  of  ideation  makes  so  few  correlations 
that  its  evidence  is  largely  negative.  It  is  not  broad  spanned 
for  the  work  given  in  these  experiments.  It  is  probably  more 
efficient  in  concentration  than  the  Visual. 

In  view  of  these  resuls  it  must  be  acknowledged  that  the 
Attention  is  a  function  of  the  co-operation  of  many  factors 
of  the  mind  and  it  takes  its  character  from  them.  The  activi¬ 
ties  of  the  Attention  will  not  be  understood  until  the  relation 
to  these  component  and  controlling  factors  is  understood. 
As  Goethe  has  well  said: 

“Das  Besondere  unterliegt  ewig  dem  Allgemeinen 
Das  Allgemeine  hat  ewig  sich  dem  Besonderen  zu  fiigen.” 


Span. 

Span. 

Span. 

Span. 


Concentration  and  Inhibition  . 


Mobility . 

Ideational  Types. 


Visual  Perception  and  Attention . 


Motor  Factors  and  Perceptual  Attention. 


Auditory  Factors  and  Perceptual  Attention. 


0.24 


0.48 

0-33 


0.63 

0.42 

0.78 


TABLE  OF  ALL  CORRELATIONS 


Concentration,  Etc. 


0.30 
— o.  12 
0.24 
0.30 
-0.15 


0-39 
o.  18 
0-39 
-0.36 
—  o.  i8 

03 


o.  12 

o-iS 

0.03 

0.09 

o-iS 

18 

09 


Ideational  Type 


0.03 
0.03 
0.15 
o.  12 
0-33 
0.03 
0.42 
0.03 
—0.09 
—0.03 


0.03 
o.is 
0.09 
0.03 
0-33 
—0.06 
—  o.  12 
0.09 
o.  27 
0.27 
—0.27 


Visual  Perception,  Etc. 


I  0-63 
I  0'09 
I  0.24 

'  0.30 
— o.  27 
0.18 
—0.30 
0.00 
0-45 
0.42 
-0.15 
-0.03 


-0.06 
0.09 
0.09 
o.  12 


0.09 

O.IS 

0.12 

-0.06 

0.03 

0.51 

0.09 

0-45 

—0.09 


0-54 
0.24 
0.66 
0-57 
0.30 
0.36 
0.30 
—  o.  18 
o.  27 
0-57 
o.  12 
0.12 
0.30 
0-33 


o.  24 
0.00 
0.30 
0-33 

-0.15 

0-45 

—  0.09 
0.00 
o.  12 
0-33 

—  0.06 
0.06 
0.12 
0.24 
0.42 


1 .00 
0.24 
0.48 
0.63 
-0.21 
0.30 
-0.39 
0.12 

O.IS 

0.45 

-0.03 

0.03 

0.63 

-0.06 

0-54 

0.21 


—  o.  27 

0.39 

0-39 
0.42 
-0.39 
18 
—0.06 
—0.12 
o.  21 
0.03 
0.03 
0.03 
o.  27 
O  33 
0.48 
0.42 
o.  27 


Motor  Factors,  Etc. 


-0.30 

-O.IS 

-0.27 
“0-33 
0.1s 
-0.12 
0.00 
‘0-33 
0.27 
-0.27 
-0,21 
-0.09 
—0.03 
—0.27 
-0.36 
-0-33 
-0.30 
-O.IS 


0.06 
■o.  18 
0.06 
0.03 
0.18 
o.  18 
0.09 
0.48 
O.  24 
0.30 
—  0.21 
0.03 
-O.IS 
—0.27 
—  0.27 
—0.03 
0.06 
— o.  24 
-O.IS 


Auditory  Factors,  Etc. 


5oav  XXV  XXVI  xxvn  xxvnr 


0.03 

0.09 

0.03 

0.09 

0.03 

-0.33 

-0.21 

-O.IS 
o. 

—0.09 

0.09 

0.09 

—  O.  21 

—  0.09 
0.09 
0.03 

—  0.09 
0.03 

—  0.09 


-0-33 

-0.33 

-0.39 

-0.39 

51 
—  0.18 
o.  18 
0-33 
-0.39 
-o.  2 
-0.09 
0.09 
-0-33 
-O.IS 
—0.48 
-0-33 
-0-33 
-0.51 
0.06 
0.24 
0.03 


0.00 
oiS 
0.30 
0-33 
o.  12 
0.09 
-0.27 
-o.  12 
0.09 
0.48 
0.48 
-0.00 
O.IS 

0.24 

0.42 

0.30 

0.00 

0.24 

•0.06 

■0-33 

■0.33 

-o.  21 


-O.O9 

0-33 

0.09 

CIS 

0.00 

-0-33 

-0.06 

-0.09 

-0.03 

0.30 

-0.03 

0.09 

0.12 

0-39 

0.12 

-O.IS 

•0.09 

015 

0.00 
■0.48 
o.  18 
0.09 
0.48 


0.03 
o.  18 
0.09 

O.  21 

-0.15 
0-39 
0.03 
-0.18 
-0.09 
-0.03 
-0.09 
-0.39 
•0.06 
-0.09 
o.  18 
0.36 
0.03 
0.42 
0.09 
•o.  12 
-0.15 
■0.24 
0.24 
•0.09 


— o.  18 
-0.21 
0.09 
0.03 
0-39 
0.03 
-0.30 

-O.IS 

015 

O.  21 

■0.45 

0-33 

0.00 

O.IS 

0.09 

0.09 

0.18 

O.IS 

0.30 

0.09 

O.IS 

015 

0.42 

0.24 

0.03 


0.21 

O.  21 

0-33 

0.36 

-O.IS 

0.09 

-0.33 

0.09 
0.03 
0-39 
-o.  21 
-0.09 
O  33 
-0.03 
-0.09 

-0.33 

o.  21 
0-39 
-0.06 

-O.IS 

0.51 

-o.  21 
0.60 
0.36 
0.09 
O  IS 


0.45 

0.09 

0.15 

0-39 

-0.21 

0-33 

-0.21 

O.IS 

-0.09 

O.IS 

O.IS 

-O.IS 

0.09 

-0.1s 

0.30 

0.09 

0-45 

0.09 

■0.39 

0,42 

■O.IS 

•0.21 

•0.09 

•0.27 

0.00 

•0.27 

0.09 


X  !J 


I 

II 

in 

IV 

V 

VII 

VIII 

IX 

X 

XI 

XII 

xni 

XIV 

XV 

XVI 

XVII 

XVIII 

XLX 

XX 

XXI 

XXII 

XXIII 

xxrv 

XXV 

XXVI 

xxvn 

xxvin 


Span  of  attention 

Span 

Span 

Span 

Concentration  and  inhibition 
Mobility 

Ideational  types  of  attention 


Visual  perception  and  attention 


Motor  factors  and  perceptual  attention 


Auditory  factors  and  perceptual  attention 


Colored  squares 
Words 

Colored  letters,  numbers  and  figures 
Totals 

(Concentration  upon  one  class  of  objects 
With  colored  background  distraction 
With  fire-alarm  distraction 
Concentration  upon  a  certain  class  of  words 
Shifting  the  attention  from  class  to  class 
The  visual  type 
The  auditory  type 
The  motor  type 
Preference  for  the  color-class 
Associating  colors  with  their  objects 
Ability  in  attending  the  color-class 
Selecting  colored  objects 
Span  for  colors 
Concentration  for  colors 
Choice  of  the  word-class 
Choice  of  word-class 
Ability  in  attending  word-class 
Preference  for  word-class 
Totals  for  auditory  factor  experiments;  span 
Words  seen,  attention  on  poetry  read 
Poetry,  attention  on  poetry  read 
Words,  attention  on  words 
Poetry,  attention  on  words. 


